# 1971 GTO... needs more umph!



## PontiacJack (Feb 7, 2005)

Hi! Sure glad I found this forum. I'm a new Goat owner but a long time (kinda) pontiac fan. I was 15 when I bought my 1st Pontiac. (1972 Lemans Lux.) I'm 21 now and just purchased some muscle. Judge orange 1971 GTO (400 w/ 4spd). Pretty much bare bone stock. I've had it for three weeks and love it. However I want to ditch the stock air cleaner. Which if I am not mistaken, comes with highly recommend carb and intake upgrade as well. Is this true? Any suggestions? I love the originality of the car and will keep all the old parts just as a precaution, but after years of body work and nose repairing (done a few for my friends ... i'm getting good) I want to learn about motors now that a actually have one worth learning about ; ) Thanks.

-Pontiac Jack

ps...

looking for a couple parts...

Hood tach
Fender Trim
Rally Clock

Thanks Again!


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## SANDU002 (Oct 13, 2004)

Start looking on Ebay and check out Year One and Ames Performance.

also check out GTOAA.COM to find a local club that maybe able to give advice on engine upgrades.


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## Guest (Feb 7, 2005)

*i can help you*

i can advise you on any low dough mods you want , been building fast poncho
motors cheap i know the right combinations ask away !


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## lars (Sep 28, 2004)

Jack -
The parts you're looking for are available from Ames and Year One.

The stock GTO 400 will respond well to a few modest performance mods:

The stock exhaust manifolds are very restrictive, as is the stock exhaust system. If you want to keep it looking near-stock, use a set of Ram Air manifolds - these flow much better. If appearance is not a factor, get a good set of headers, like the Hooker Supercomps, and run them through a 2-1/2 inch system with a good set of Flowmaster mufflers. This will wake it up right away.

The stock cam in your car is most likely the old reliable "067" if you have an automatic. It could even be an "066." This cam is a bit conservative, to say the least. If you want a factory cam with a smooth idle, step up to the "744" (Ram Air III) or pick one of many available dual pattern aftermarket cams in this basic lift/duration range. There are significant improvements to be made with a modern cam. Install a new timing chain to make things nice and tight.

Along with the cam, upgrade the valvetrain with a good set of springs, keepers and retainers. The stock springs will float at a surprisingly low rpm.

The stock ignition curve is too slow for a performance application. Curve the distributor to provide 16-18 degrees initial advance, 36 degrees total advance, with all the advance coming in at 2500 rpm. This makes a HUGE difference in throttle response and performance.

The stock cast iron intake is OK, but you can get a noticeable improvement using the Performer RPM intake. Use any 750 cfm carb set up correctly (the stock Q-Jet is 750, and will perform well if set up right). Swapping air cleaners from a stock dual snorkel to an open element isn't going to gain you much other than some chrome flash.

These simple mods will produce a fairly significant change in performance of your otherwise stock 400.


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## 05GTO (Oct 6, 2004)

Also, keep in mind that 1971 was the first year the GTO came with a lower compression ratio of 8.2:1 down from the previous years of 10.75:1, This was when the big 3 started scalling back muscle car performance and emissions started coming into the picture. The 1971 GTO was produced with a stock HP rating of 300hp down from 360 in the previous years. Also, the 1972 GTO saw a loss of another 50 hp.

In addition to lars suggestions, I would shop for a new set of heads to get the compression ratio back to 10.75:1.


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## PontiacJack (Feb 7, 2005)

Thanks a lot everyone. I actually opted to take care of a few asthetics 1st. The previous owner let the hood flip up while driving and curled the hood beyond repair. Lost some wipers and ruined the hinges in the process. I Have a hood coming from Long Island (that was real hard to find!) hinges, wipers, and a reproduction latch for good measure.

The goat definatly needs some help breathing. I know a shop in San Mateo (Pennisula) that did the exhaust (complete) on my friends cherry '68 camero for $900. Included hedman headers, pipes, dual chamber flows, and installation (very clean job the camero was previous lower and you can't see a bit of the exhaust... its tucked very well.) Anyways my question is, is it tacky to install ram air iii for a gto originally NOT having it? How much does it cost, how hard is it to find parts? I've seen some pretty good looking setups on ebay for $950, including hood ducts, air cleaner etc.... is the original ram air iii intake ness.? how about the ram air iii heads? Or can I find compatible aftermarket parts? I remember reading that lots of headers don't match up well with ram air iii heads... i ask because i am leaning towards installing ram air, but don't want buy into a exhaust system and find out i have to chop up my headers and replace all together. I know I could probably get lots of info from this exhaust shop i want to go check out real soon. But wanted the poncho prespective... espically on the tacky-ness question.

thanks


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## 67DROPTOP (Dec 17, 2004)

It won't help to add all the Ram Air features unless you have the Ram Air Heads. As far as performance and umph goes, the skies the limit. It depends on how much you want to spend, and how deep into the engine you want to go. If your bottom end (block is still good) is ok I would start with the heads. IMO the biggest upgrade on a Pontiac are the Headsand Cam.You can go wth repo aluminum heads ie: Edlebrocks ( designed like the ram air head) Kaufmans( a new ram air D port head), or a used set of Pontiac Large valve cast iron heads that are milled to attain a good commpression ratio. When designing your engine always keep in mind the compression ratio. The higher the ratio, the higher in octane fuel your car will need. Then choose a Cam to match the Heads, then an exhaust system to match both. There are so many different combo's it can become confusing.
Before spending any $ I would recommend you purchase Jim Hand's book on building performance Pontiac engines. Between the covers are a wealth of information and a list of builders and the combinations they use.
Hope this helps.


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## lars (Sep 28, 2004)

PontiacJack said:


> Anyways my question is, is it tacky to install ram air iii for a gto originally NOT having it? How much does it cost, how hard is it to find parts? I've seen some pretty good looking setups on ebay for $950, including hood ducts, air cleaner etc.... is the original ram air iii intake ness.? how about the ram air iii heads? Or can I find compatible aftermarket parts? I remember reading that lots of headers don't match up well with ram air iii heads...


There's nothing special about a Ram Air III. Ram Air III used the "744" cam on the 4-spd engines, and the plain ol' "068" cam in the automatic cars. The Ram Air III was available in 1969 and 1970, and featured plain "D"-port heads with slightly higher compression than the standard D-port heads, but no more flow. The RAIII had fairly good exhaust manifolds, and came with a cold air induction package. None of the cold air package parts will fit your '71, so there's no point in getting a "Ram Air III" package for your car. The Ram Air III heads will bolt on, and will only give you the advantage of higher compression than your stock '71 heads. There are no problems with headers for the RAIII heads - they are regular D-Port heads that accept any Pontiac "A" body header.

If I were you, I'd skip on the RAIII conversion: the "744" cam is not computer optimized, making the cam good for its time, but a poor choice compared to modern cams. The RAIII heads provide compression, but not that good flow. There is no difference between a RAIII intake and a standard Pontiac 4-bbl intake: it's a regular cast iron intake.

If you want to make the car quick, go with a set of aftermarket heads, a good aftermarket cam, a set of headers, and a good aftermarket intake. Things have come a long way since Pontiac built these engines in 1970, and you'll be paying a premium for the "original" '69-'70 Ram Air III parts that really won't gain you much (and the Ram Air stuff won't fit anyway).


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## Guest (Feb 25, 2005)

*heads schmeads*

ram air schram air, the only differance are sd heads round exhaust ports,and the most important thing 4 bolt mains forged crank , all d port exhaust ports will flow about the same all the way across the board, the differance in d ports is the combustion chamber size period will determine compression ratio,
if you got d ports it will only make torque to 5500 rpms period. the extreme
drop in the exhaust ports were engineed not to flow over 5500 rpm because
the bottom ends were weak. the sd 4 bolt could turn over 5500 rpms but the 
chambers were 120ccs too big to build compression. flat top pistons,small chambers,1.76 rockers,screw in 7/16 big block chevy studs,remachine spring seats in the heads run small block chevy springs,thats the ticket flat tappet cam 556i 565e 112 ctr cam 455 cubic inch toque from 1200rpm to 5400rpms
now you cooking this combo will spank the z06 i know it will it ran 10.99s
in a 4,000 lb 70 gto convertible. grasshopper you now have the secret!

keep the overpriced aluminum heads run steel its for real i know more ask me!!!!


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## lars (Sep 28, 2004)




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## PontiacJack (Feb 7, 2005)

05GTO said:


> Beautiful car! I modified the picture a little, here is the url if you want to add it to your signature.
> 
> 
> 
> ...


WOW... looks great! Thanks for customizing that huge picture for me. Thats really something. I posted it from work were i had no means of editing it. (warranty claims admins at a mercedes dealers don't really get all the goodies on their computers)


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## PontiacJack (Feb 7, 2005)

Damn do we have some serious gear heads up in here or what? Haha, thats great. Thanks guys(and or ladies)... I'm working on my membership to a local GTO club in San Mateo but they meet on tuesday nights (i've got night school) So I'll have to work something out for that deal. Secondly I've been looking around for the parts... OPGI seems to be a great place just for the little touches etc. EBAY has got me access to a hood latch for my 72 LeMans, Hinges for the GTO and form the same guy a real bonafide 1971 GTO hood... thous hoods and straight up difficult to find. Local junk yard wanted 650 for one that needed extensive repairs, half the other places laughed when i asked them if they had one. Thanks for the EBAY idea thou I am a seller on there now letting go of my extra LeMans parts (good easy dough maker) mercedes benz take offs and a slue of manuals i've got my hands on.

oke ... time to stop stalling and get to the point. I never really drove a straight up muscle car untill i bought this goat about a month ago. I really did get to much time to learn to drive the car either becuase i only took it out on the weekends and the weather really blows big time here in california currently. (plus i have got little boots in the rear 215's big no no says my gear head buddies. I agree) now heres the skinny... I've been asking for the power... I feel it but wasn't really seeing it ... my clutch was giving up... just last week my buddy and i took a spin and it was obvious... my clutch was toast! I've got some learning to do but i don't think it was anywhere near new or good shape when i originally bought the car.... 

QUESTION

OEM clutch or Aftermarket... I know a big part of it has to do with how much are you willing to spend but is the extra dough worth it? Suppose a car was driven fairly well woudl the aftermarket clutch last longer then the OEM or will it only grab better?... when you change the clutch... would it be wise to replace the u-joints? and what are peoples thoughts on a lighter drive shaft?

I have thought about it and decided to work up a little more research and buy the pontiac engine builders book to match up the right stuff. I dont' want to go too deep in the engine... but some AM heads and a mild cam sound like a nice start...

Last thing... would most of you guys go with mating a cam and set of heads prior to getting your exhaust done? Thanks Again.


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## billy177 (Mar 6, 2005)

ramairws6 said:


> ,small chambers,1.76 rockers,screw in 7/16 big block chevy studs,remachine spring seats in the heads run small block chevy springs,thats the ticket flat tappet cam 556i 565e 112 ctr cam 455 cubic inch toque from 1200rpm to 5400rpms
> now you cooking this combo will spank the z06 i know it will it ran 10.99s
> in a 4,000 lb 70 gto convertible. grasshopper you now have the secret!


if you need that to run a 10.99 in a gto then you have prolblems, big prolblems

aluminium heads are a nice addition because with the 9.5 compression allowing you to run on pump gas. and they dissapate heat better then iron heads. (aluminum heads allow you to run a full point higher compression)


I can tell you to skip the ram air manifolds and go strait for the headers. would will only gain minimal power by just switching types of manifolds.

the new dual pattern cams are a lot nicer and more streetable then the old single pattern ones

anything over 5500 rpms and you are wasting your time on a pontiac. they were not designed to go higher then that and you do not need to rev it higher to go fast.

10.75:1 on iron heads is just too high for pump gas these days, in fact many people are opening up their combustion chambers to help lower it.

http://forums.performanceyears.com/eve/ubb.x

i would like to refer you over there as they have many more topics on the subject then here and the people giving advice actually have first hand expierence and will be able to help you much better then most of the people here. with the exception of a few


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## cyborg512 (Jan 13, 2005)

Best and cheapest upgrades I ever did to my '69 400/3spd goat was to ditch the QuadraJunk carb and ignition system. I loved the Holley QuadraJet replacement and Mallory hot wire ignition. I chose for the carb mechanical secondaries and 650cfm. It woke the car up in a big way for only a few hundred bucks. Also check your exhaust. If you have duel pipes with any rust and rubber hangers, I cut both pipes about 2 inches in front of the mufflers (it was rusted out on one side already), used straight, chrome exhaust tips to reconnect to the mufflers but did NOT clamp the muffler end. This allows the mufflers to swing back on extreme acceleration and open exhaust! It'll roar like a tiger till your velocity equalizes and closes the gap. Even a small thing like that can give you an edge off the line. either that or pay a fortune for headers and pipes that are at LEAST 4" in diameter for max flow. I kept the stock intake manifold and it performed great with the new carb. This was 25 years ago though and since I've been out of the muscle car scene for 20 years, may not be good advice any more.

cy


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## billy177 (Mar 6, 2005)

you do not need 4 inch exhaust to make good power.

you can pick up a set of cheaper quality headers for around $250 that will give you decent flow. and dual 3 inch is perfect for a moderate built 455 and up and dual 2.5 si good for the 400 snd such. rember these engines only need to turn 5k.


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## cyborg512 (Jan 13, 2005)

heheh, ya know I was gonna say 3" pipes but then I over engineer everything these days. Thanks for the info!

cy


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## talktorque (Mar 6, 2005)

*Big GTO power on a budget*



PontiacJack said:


> Hi! Sure glad I found this forum. I'm a new Goat owner but a long time (kinda) pontiac fan. I was 15 when I bought my 1st Pontiac. (1972 Lemans Lux.) I'm 21 now and just purchased some muscle. Judge orange 1971 GTO (400 w/ 4spd). Pretty much bare bone stock. I've had it for three weeks and love it. However I want to ditch the stock air cleaner. Which if I am not mistaken, comes with highly recommend carb and intake upgrade as well. Is this true? Any suggestions? I love the originality of the car and will keep all the old parts just as a precaution, but after years of body work and nose repairing (done a few for my friends ... i'm getting good) I want to learn about motors now that a actually have one worth learning about ; ) Thanks.
> 
> -Pontiac Jack
> 
> ...



Checkout this site it'll answer all your questions 
www.nitemareperformance.com 
there's lots of great stuff here but be sure to read their article called
"How to 11 second your GTO on a budget" article!
http://www.nitemareperformance.150m.com/11seconds.htm


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## lars (Sep 28, 2004)

ramairws6 said:


> it ran 10.99s in a 4,000 lb 70 gto convertible.
> keep the overpriced aluminum heads run steel its for real i know more ask me!!!!


What a bunch of BS.
For a 4000-lb car to run 10.99 takes 600 rear wheel horsepower, or about 775 horsepower at the flywheel. Iron heads flow less than 220cfm on the intake side, and seldom more than 230 with extensive porting - it doesn't take a wizard to calculate maximum obtainable hp, and it isn't 775. Please show me a normally-aspirated iron-head 455 in a street-driven car producing 775 hp, and show me any track in the world that would allow that 10-second convertible to run without a full NHRA-certified cage.

Here's a real dyno run of a very nice running 455 street engine. It uses the Edelbrock heads and a CompCams hydraulic flat tappet cam. Performner RPM intake and an 850 BG carb with a good set of headers. Good light weight pistons were used on Chevy rods to keep the assembly reliable up through 6000 rpm. The spread sheet chart gets a little jumbled when imported into the Forum format, but I think you can make out the numbers: Peak hp of 588 and 603 torque. Dyno used was the Westech Engine Dyno in L.A.:


Listing of: (memory data) 
Channel Group: Corrected Torque and Power Page 1 
Printed on Nov. 2, 2001 16:14:21 
Test Description: Accel. Test - 300 rpm/second 455 Pont 

EngSpd	STPTrq	STPPwr	BSFC	FulA+B	WtrOut	LamAF1	ManVac	Oil P
RPM	Clb-ft	CHp	lb/hph	lb/hr	degF	Ratio	inHg	psig

3500	575.2	383.2	0.567	193.1	107	13.6	0.0	91.7
3600	574.9	394.0	0.555	194.1	107	13.6	0.0	91.6
3700	579.0	407.9	0.511	185.0	108	13.6	0.0	91.9
**	3800	585.2	423.4	0.481	181.0	108	13.6	0.0	92.5
3900	589.7	437.9	0.453	176.2	109	13.6	0.0	93.1
4000	592.0	450.9	0.438	175.1	109	13.6	0.0	93.5
4100	596.5	165.7	0.422	174.5	109	13.6	0.0	94.4
4200	601.1	490.7	0.416	177.2	109	13.6	0.0	95.8
4300	602.9	493.6	0.416	182.3	109	13.6	0.0	96.6
4400	603.7	505.8	0.416	186.4	109	13.4	0.0	97.1
4500	601.0	515.0	0.419	191.4	109	13.4	0.0	97.0
4600	597.4	523.7	0.423	196.8	109	13.4	0.0	96.6
4700	596.5	533.8	0.423	200.6	109	13.4	0.0	96.1
4800	595.1	543.9	0.423	203.9	109	13.4	0.0	95.8
4900	592.7	552.9	0.425	208.1	109	13.3	0.0	96.0
5000	588.0	559.8	0.435	215.6	109	13.3	0.0	94.7
5100	582.6	565.7	0.436	217.9	109	13.3	0.0	92.3
5200	571.5	565.8	0.443	221.5	109	13.3	0.0	89.6
5300	564.3	569.4	0.439	220.4	109	13.3	0.0	88.8
5400	556.5	572.2	0.435	219.4	109	13.3	0.0	87.7
5500	551.4	577.5	0.443	225.2	109	13.3	0.0	88.5
5600	547.3	583.6	0.454	233.6	110	13.2	0.0	88.3
5700	540.6	586.7	0.465	240.2	110	13.2	-0.5	86.1
5800	532.9	588.5	0.474	245.1	110	13.2	-0.5	87.8
5900	520.8	585.0	0.487	250.3	110	13.2	-0.5	94.6
**	6000	508.9	581.3	0.501	255.2	110	13.2	-0.5	95.2

**	Range: 3800 RPM - 6000 RPM 
AVG:	4900	574.7	533.2	0.442	208.6	109	13.4	-0.1	93.0
MIN:	3800	508.9	422.4	0.416	174.5	108	13.2	-0.5	86.1
MAX:	6000	603.7	588.5	0.501	255.2	110	13.6	0.0	97.1


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## billy177 (Mar 6, 2005)

first off the convertable weighs 3664 not 4000 pounds.

and does not take 775 flywheel horsepower to run a 10.99 second quarter that is just nuts. and i have never heard of a drivetrain causing a 175hp loss.

and it does not take chevy internals to keep the bottom end reliable.

http://www.fastcarvids.com/videos/jtaylor.wmv
around 550 hp


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## lars (Sep 28, 2004)

Billy -
In his post, the guy stated the car weighed 4000 lbs. Getting a 4000-pound car into the 10s requires 600 at the wheels. If the car actually weighs 3664, it takes about 550 at the wheels - correct as you stated. But he said 4000...

I've done quite a bit of dyno work - both engine dyno and chassis dyno testing. On the engine dyno, we typically run the engines in their "gross" hp configuration: Bell inlet on the carb; open headers with collector extensions; no fan; no alternator; no power steering pump; etc - same method used by GM in the good days of gross hp numbers. Typically, when we configure into the "net" configuration we see about a 10% reduction in flywheel horsepower. Some engines are worse than others depending on the actual installed ("net") configuration - if you look at the GM published net versus gross on the early 70s big block Vette engines, they were seeing up to a 20% horspower change between gross and net, and this is not counting driveline losses.

Further, I see very consistent reductions once the engine is in the car. Very consistently, driveline losses on an automatic car are in the 18-22% range (I've seen as much as 25%), and manual cars see a very consistent 15-17% loss between flywheel and rear wheels. Thus we see that actual % reduction in horsepower from rear wheel power to gross flywheel power is quite a bit in excess of 20%. Getting 600 actual rear wheel horsepower will (conservatively) require about 750-775 gross flywheel horsepower to compensate for driveline losses and net-to-gross conversion. As noted, and I think you'll agree, this would be tough to do on factory cast iron heads.

Your 550 rear wheel horse requirement is more achievable. This implies about 700 gross at the flywheel. Jim Taylor, Butler, Whitmore, Crocie, Logan and others have managed to get this level of power from their Pontiacs. But they're not street-driven cars.

Getting a 455 into the mid/high-500 horsepower range (gross - implies rear wheel horsepower 425-450) is easily achievable with common components and a good set of heads. In a 3600-pound car, this would put you into the high 11's, and that's a darned fast street car. If you can then lighten the car up to about 3100 pounds, it can break you into the 10s.

...but you won't do it pushing 4000 pounds down the track.


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## PontiacJack (Feb 7, 2005)

GOD DAMN RAIN... wasted the goodguys show over here in the bay. I was going literally annoying every pontiac owner with a thousand questions. I didn't get any replies on the clutch question, but looks like i'm going out to buy a shach clutch kit (10 1/2") and use my dads lift to put that sucker in. plus oil change and the basic.

QUESTION

is center force really that much better?


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## billy177 (Mar 6, 2005)

better then what centerforce is pretty good, you could awalys get an 11inch flywheel and clutch


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## lars (Sep 28, 2004)

We've been running Centerforce setups in our Pontiacs and Vettes out here in Denver, and they run very good. The standard Centerforce is no different from any other clutch system. The Dual Friction setup, however, is a unique design that really works well. We've had 2 issues with these systems:

1. The DF system usually requires that you install a clutch fork pivot ball that's about .100" taller than stock. If you don't, you will run out of clutch adjustment on the adjuster rod. We've been using the adjustable pivot balls, setting up the height .100" taller than stock and then LocTite'ing the balls in place so they won't come loose on the adjustment.

2. At idle & low rpm, the counterweights on the DF system will often rattle, making the car sound like you have a throwout bearing in the failure mode. Some people find this a little irritating. 

We're using 11-inch systems in all our big block Chevy stuff and all our Pontiacs, and using the 10.4" standard clutches in the small block Chevy applications.


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## Fawkes (May 3, 2005)

lars said:


> Things have come a long way since Pontiac built these engines in 1970


The funny thing about this comment is that the Edelbrock heads are patterned after the original Pontiac heads (I'm not sure how much of an improvement Jim Buttler has made on with his new head). The best aftermarket street cams use the factory Pontiac grind. Aftermarket intakes flow only slightly better than the factory units (like the heads, the aluminum aftermarket units are much lighter). And short of all-out race headers, the factory RA headers flow awesome and fit better than any aftermartket header.

Bottom line, technolgy has come a long way, but not all that much better than what the Pontiac Engineers developed way back when. All you have to do is look at Jim Hands wagon and you'll see how much potential that "old" technology really is capable of.

That's just my two cents though.


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## PontiacJack (Feb 7, 2005)

update...

i ditched the exhaust plan... something came up. my q-jet took a dump on me. puking fuel everywhere and it was running like a junkyard turd. finally made up my mind and bought a edelbrock 750 cfm elec. choke. edelbrock performer rpm intake and a cam kit. got the intake and carb on and took it for test drive ... out of no where i have some massive coolant leak. bummer. so front timing chain cover reseal kit just to get it cruising... probably mid summer i'l have a garage for my very own self and yank the motor to plop on some heads put in the cams and update the exahust.


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