# Opinions needed - what engine should I use?



## TK69tempest (Feb 28, 2011)

I'm rebuilding my '69 Tempest and suddenly have several engines to choose from. I can use the original 350 and make a stroker out of it, build a 400 with mild improvements, or build a 455. I'm wanting to have good performance and reliability while still using pump gas. Opinions, pros & cons, or other options and suggestions?


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## JustAl (Mar 20, 2010)

Your budget is always a factor. With all the current aftermarket parts the 400 is a great way to go. Many of major Pontiac engine builders offer rotating assemblies, with crank rods pistons rings and bearing all included. With a .030 overbore a 460+ cubic inch engine is easy to obtain. Keep compression at no more 9.5 for iron heads or 10.5 for alum if the budget allows. Comp cams have a couple of good grinds that make excellant power with good street manners. Dual plane intake with with a sensible carb, usually vacuum secondary for street use and cars this heavy. I'm sure others will weigh in, and they will have different opinions.


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## Mr. P-Body (Jan 20, 2011)

Actually, Al nailed it. A 400 block with a stroker 'kit" will be the toughest and most powerful combinatin. Also, as he said, "budget" plays a key role. An iron-headed 461 making 500 HP and 550 lbs. of torque will cost in the $6K range. A 600 HP aluminum-headed monster will cost $7,500-plus (if done "right"). One thing, Comp offers more than a "couple" good grinds. And the catelog is not the best "source" for Comp cams for the Pontiac. Custom grinds are available to have the same level of performance as the Chevy and Ford boys "enjoy". 

This may "sound" a bit strange, but it's true. The 400 block is physically stronger than 455. Consider the "centers" are all the same, essentailly the same castings. The "hole" down the middle (main tunnel) is smaller in the 400, leaving more "meat" in the bulkheads, the area of the block known to fail in 455s.

A 400 is a strong performer, too. One can easily build a 400 HP 400 for less than $5K. The 400 at this level is a bit "rowdier" than a 461, but still completely drivable and pump-gas "friendly". The "cool" thing about 400 is it's ability to rev and "live". With a few modifications internally, 7,000-plus with no worries. It also tends to get "underestimated" by competitors. SURPRISE!

I would avoid the 350 "stroker". While it seems attractive, the return on "investment" is much better with the larger displacements.

Once you decide, for a complete "package" to make good power and live, repost and I'll outline a "strategy".

Jim


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## Eric Animal (Oct 28, 2007)

:agree.......100% ...Unless you have a big budget and a 35 year old dream of whirling pulleys sticking throug your hood! Build a "nice" 400. :cheers...the key is research ALL the parts for best compatibility, so you have a happy drive train.!


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## Josh.AZ.GTO (Jul 11, 2009)

I was thinking about stroking my 350 but now I'm thinking about just giving it an overhaul instead. Save my money for a 400 or 455.


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## freethinker (Nov 14, 2009)

Josh.AZ.GTO said:


> I was thinking about stroking my 350 but now I'm thinking about just giving it an overhaul instead. Save my money for a 400 or 455.


there is no reason to put a lot of money into a 350 pontiac unless you are trying to build a numbers matching car.


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## TK69tempest (Feb 28, 2011)

It was my original intention to build a 400. Then I read about the stroker 350 that PPR was building, and since I already had a 350 I figured I'd research it. Shortly after that, a friend offered a 455 for a good deal, so I figured I'd look into that also. I'm not looking to build the fastest car in town, but I wanted something better than the original 2 barrel 350. I don't have a huge budget - I'll be doing all the work myself (except machining), so I should probably stay with a design that is proven to work well.


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## freethinker (Nov 14, 2009)

TK69tempest said:


> It was my original intention to build a 400. Then I read about the stroker 350 that PPR was building, and since I already had a 350 I figured I'd research it. Shortly after that, a friend offered a 455 for a good deal, so I figured I'd look into that also. I'm not looking to build the fastest car in town, but I wanted something better than the original 2 barrel 350. I don't have a huge budget - I'll be doing all the work myself (except machining), so I should probably stay with a design that is proven to work well.



i agree. do you want to be cool or practical? unless you have a need for a numbers matching engine or are restricted by class rules there is no need to waste money on a 350. there are much easier ways to get to your goal with less work and money. a 350 has nothing going for it that a readily available 400 cant do easier and cheaper.


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## TK69tempest (Feb 28, 2011)

I'm really thinking a 400 is the way to go. My goal is to be able to get 400-425 hp and still run on 91 octane or less. Any ideas on a setup that would meet that?


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## freethinker (Nov 14, 2009)

TK69tempest said:


> I'm really thinking a 400 is the way to go. My goal is to be able to get 400-425 hp and still run on 91 octane or less. Any ideas on a setup that would meet that?


well how much do you want to spend. money is speed. how often will you need that 400 hp? personally if i were on a budget and only wanted an occasional street blast i would put together a good stock 400 with an xe268 cam and top it off with nitrous. cheapest way to get there.


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## likethat (Oct 5, 2007)

I rebuilt a guy at works 70 firebird, suspension and motor. It was a very clean all original from his aunt. I rebuilt the 350 with a cam and pistons from ebay, some speedpro 30 over 4 valve flat tops used, edelbrock 4bbl intake and carb new, a nos 068 cam, and stock exhaust manifolds with 2 1/2 dual. Had some mild head work and freshened the rest up with new parts from ebay and the parts store. All in all it was around $1100 with machine work and parts. It wasn't a barn burner but had a lot more power then the 2bbl stock 350 set up. Which is some where around 225hp. It has been going strong as a daily runner since 2003 to now. It has a nice mild lobe idle and has good power from off the line on.


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## BearGFR (Aug 25, 2008)

TK69tempest said:


> I'm really thinking a 400 is the way to go. My goal is to be able to get 400-425 hp and still run on 91 octane or less. Any ideas on a setup that would meet that?


As a matter of fact, I do  Having recently built one myself (with Mr. P-Body's recommendations). 

First of all though, look into the mirror and repeat after me:

"First and foremost, the goal of any magazine is to turn a profit by selling advertising. They are not interested in helping people nor even in necessarily telling the truth."

Now, for your perusal, please view the dyno sheet for my original, numbers-matching, 1969 GTO "400".

It doesn't meet your criterion of making "400-425" hp though, it makes 492 

This motor is running cast iron 1969 Pontiac heads, factory iron intake, and a 455-SD QJet. It's happy on 93 octane pump gas and has a static compression ratio of 9.46:1.






Bear


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## TK69tempest (Feb 28, 2011)

Nice - Can you help a guy out with practical ideas? Cam, rods, pistons, etc. - I don't necessarily need to copy yours, but I definitely like what you've got there!
:cheers


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## BearGFR (Aug 25, 2008)

TK69tempest said:


> Nice - Can you help a guy out with practical ideas? Cam, rods, pistons, etc. - I don't necessarily need to copy yours, but I definitely like what you've got there!
> :cheers


Sure. My rotating assembly is an Eagle stroker "kit" (cast crank, forged h-beam rods, KB/Icon forged pistons with additional dish volume cut into them) - procured and balanced by CVMS. 

My cam is a Comp Cams solid roller, custom grind designed by Jim at CVMS, using Comp Endurex lifters, Scorpion 1.65:1 rockers, Howard's valve springs, Comp titanium retainers and super locks. 

I'm using a Comp Cams stud girdle (I'm kinda proud of the way I "stealthed" all that to fit under the factory valve covers, can you spot what I did?)  Here's a hint.


Also inside is a Milodon windage tray, Milodon main stud kit, lifter oil feed restrictors (because I'm running a solid cam), Comp Cams custom length pushrods, Melling high volume oil pump, Milodon pickup, Nitemare Performance oil pump plate, drive shaft, and cam plate, Comp Cams 9-way adjustable billet timing set. 

Outside, I'm running a Milodon pan, RobbMc high torque starter, RobbMc mechanical fuel pump , regulator, and filter, KRE timing cover (only because I broke my original one trying to press out the old corroded water sleeves), SFI-rated harmonic balancer and flex plate, factory cast iron intake (port matched to the gaskets/heads), Proform HEI, and a service-replacement 455SD Qjet. 

The exhaust system consists of a set of Doug Thorley D-567 headers (that I had coated by Jet Jot), , going into a Pypes 2 1/2" system with their X-change crossover and Racepro mufflers. 

For cooling I've got an aluminum radiator from Mark 7 with twin electric fans.. 

The rest of the drive train has my original TH400 that's been gone through with "all the good heavy duty stuff" behind a custom 10" 3200 stall converter, drive shaft loop, and a new Moser 9" Ford rear with a Wavetrac diff and 3.50 gears.  Rear suspension has Spohn adjustable chromoly upper and lower control arms, UMI rear control arm braces, and Spohn ProTouring rear sway bar. 


For brakes, I engineered my own hydroboost system using new/reman components from NAPA with custom hoses, Wilwood adjustable proportioning valve, and Wilwood 4-piston brakes.

I know that's more than what you asked, but the point (besides just me jumping on the opportunity to show off a little ) is that you really do have to think of a car as a complete system, not just a motor with wheels. Everything is connected to everything else, and once you start changing things - it ripples. For example --- the cam I'm running made it so that there really wasn't enough manifold vacuum to reliably operate the power brakes, so that led to the hydroboost. The power this motor makes would have chewed up the factory 10-bolt pretty quickly, so that led to the 9-inch. The factory windage tray wouldn't clear the stroker crank, so that led to the Milodon pieces.... etc.


Bear


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## TK69tempest (Feb 28, 2011)

The spacers are a great idea to get that extra clearance and keep the stock covers. Definitely will go with electric fans on the radiator. What are the thoughts on electric water pumps? My Tempest didn't have power steering or power brakes - I'm not sure I want to add them. I've seen 4 wheel non-power disc brake kits and manual rack-and-pinion systems and they have really piqued my interest.


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## TK69tempest (Feb 28, 2011)

Also - my 69 has a two speed transmission - I'm wanting to put in a TH350 or TH400. Do I need short tail or long tail?


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## Chris Holabaugh (Jan 18, 2009)

I have 65 GTO with a 455 that has 500 plus horsepower and I don't use electric fans. I have a aluminan high volume water pump and a Rodney Red aluminan radiator. I use the stock declutching fan with a fan shroud and on the hottest summer days the temp only goes to 185. I painted the radiator black so that the engine would look like it was done in the sixties.


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## Mr. P-Body (Jan 20, 2011)

Short tail... The TH350 will literally "bolt right in". The TH400 is far stronger. It will need a bit of driveshaft work (shortening). Not a big issue.

Jim


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## Cpldavis37 (Aug 20, 2009)

If you want 400-425hp and your on a budget you could just pickup a stock 455 with some head work, electronic fan, and a very mild cam, and maybe forged pistons you would be very close to 400-425. If you found a deal you could do this for a few thousand. I am pretty sure a 455 had 360hp from the factory. My 455 has all of this work and more and I am only into it for 2500 or so. 

Just some advise, I find it best not to keep a running total on paper. That way the wife will never know. And the less she knows the more I can spend.:lol:


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## Mr. P-Body (Jan 20, 2011)

ANY "stock" 455 is living on "borrowed time" unless the connecting rods are replaced.

FWIW

Jim


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## Cpldavis37 (Aug 20, 2009)

I disagree with that. The 455 can still be a great engine and it can make good hp without getting to radical or expessive. In my case I did not have 5-6000 to spend, but I was able to meet my hp goals for under that. Only time will tell if you are right.


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## BearGFR (Aug 25, 2008)

Cpldavis37 said:


> Only time will tell if you are right.


True 'dat  ... and Mr. P Body has been making a living building fast Pontiacs (and other makes) longer than a lot of folks on here have been breathing. 

It's true that 400 blocks are inherently stronger than 455's, and also true that especially in 455's the stock rods are usually the first things to "go". That doesn't mean it's not possible to build one on a budget using stock pieces and "keep it together' if you're lucky and don't go overboard on it, don't over-rev it, etc. 

You just won't be likely to be able to reliably "get" everything that those cubic inches would be capable of delivering unless you add some strength with better rods and a smaller journal block.

Part of the fun of this whole deal is putting together your own solution in your own way. If I wanted a "cookie cutter motor", I'd build a ::cough, spit::  chevy.

Bear


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## Mr. P-Body (Jan 20, 2011)

Agree or not. Irrelevant. There are 100 Pontiac V8s in the scrap heap with cast rods hanging out of them for evey one on the street that has "survived". For very little more than the cost of rebuilding the cast rods, you can have 5140 forgings. VERY "cheap insurance" against a chronic issue with the ol' *****. Protecting your "investment" (bad choice of words for an engine, particularly a high performance one, but hey, I can't think of a better word) is the BEST way to save money in the long run. 

Just for "the record", a machine shop like mine makes more money rebuilding the old cast rods than we do selling the new ones, so please, set that argument "aside".

PAX

Jim

p.s. Bear "treed" me... -


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## JustAl (Mar 20, 2010)

Again my $.02 worth. Yeah, years ago the 455 was, in my opinion, the way to go. But since the advent of "stroker " cranks that are affordable, and the widely available 400 block, that makes it a better/cheaper choice. The 455's are short in supply and over 25 years old. The rods in Pontiac engines have always been the weakest link, gotta agree with the "P" man. I still think a 400 with a stroker "kit" is the best way to go, all the displacement without the rarity and inherent cost. Torque on the street is a wonderful thing. Love them cubic inches, just keep it under 6000 RPM, or so. And a well prepped Quadrajet is a fine carburator.


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## Mr. P-Body (Jan 20, 2011)

Al,

Just for "clarity", the 400 block is not only more available, it's actually significantly stronger than any of the 3.25" main blocks (POSSIBLE exception, 421SD). The "hole" down the middle is smaller, leaving more "meat" where it's needed the most.

Corey Thompson's 461 ('71 400 block) has 545 passes on it now, and the pan has never been off. He shifts at 6,400. Greg Miller's car goes deep in the 10s, too, and he shifts at 6,600. Why the 6,000 "limit"? The heads and valve train have become the limiting factors for revving (just like the "other" guys) the Pontiac these days, not the rods. In fact, Dirty Bird "sees" 9,200 every pass... JUST LIKE the Hemis...-

Jim


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## JustAl (Mar 20, 2010)

Mr. P, Yeah that's what I meant when I said "better". The 400 blocks are stronger, it's my understanding the large diameter journals really weren't needed, just an over-engineering idea. 20 years ago putting a 455 crank in a 400 block while possible, was frequently done wrong and was somewhat expensive if done right, as I recall the thrust surfaces on the crank weren't compatable. I think we're on the same page. That said I've got a 455,why..? cause I started buying the rotating parts for it over the years and refused to let them go to waste. If I were to do it over again I'd opt for the 400 in a minute. The 6000 RPM "or so" number I was referring to was taking into consideration the valve train issues, certainly higher limits are possible but my thoughts were based on a mostly street driven application. 
Al


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## Mr. P-Body (Jan 20, 2011)

Al,

No sweat, dude. I'm just pointing out what we do with them today.

Ken Keefer (aka Pontiac Dude) has a "shimmed bearing" kit for using the factory large-journal cranks without the need for welding. It consists of an Olds thrust bearing (same housing bore) with .030" shims behind the flange for support. Just installed a 455 crank in a 400 last week using it. 

In olden times, some would weld the thrust face and regrind. Unfortunately, welding a cast crank can be "iffy" at best. I also have a 421 SD (990 "Kellogg" forging) crank here that had been modified in the '60s, with 3" mains and a welded thrust. It's cracked, but not at the thrust... On rod #2... I have no idea the "history" of it, but it was rumored to come out of one of Joe Weatherly's 421s for the '62 NASCAR season. 

As for the rev "limits", the head flow and camshaft are now the "gating factors", not the bottom end's ability to withstand it. The valve train has always been one of the strong points of the Pontiac. I know the Ram Air engines were good enough to rev themselves to death, quite literally. The rods couldn't take it. Now that we have "flow" to go along with the "other" engines, and good rods, we can rev with the best of them. Wait.... Pontiacs ARE "the best of them".... What WAS I thinking...

Jim


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## jetstang (Nov 5, 2008)

Cpldavis37 said:


> Just some advise, I find it best not to keep a running total on paper. That way the wife will never know. And the less she knows the more I can spend.:lol:


LOL, I agree, I used to tally it up, but now find I can lie to myself easier if I don't track it. Easier to deny the extra thousands dumped into it..:cheers
Can you use a long shaft 400, I got one in a combo out of a big car, good tranny, want to put it in my 66.


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## JustAl (Mar 20, 2010)

Mr P. Please don't get me wrong, not trying to be a jerk. I'm just an old school kind of guy. Pontiac....you bet, back in 1965 I built a 413 (1/8 over 389) with a Racer Brown roller, Forgedtrue pistions (sic?) a S.D dual quad set-up(wish I still had it), Mallory dual point, etc etc and put it in a 1953 Chevy, yeah Pontiac engine in a Chevy!! and ran A/Gas, with terrible results I might add. First of many Indians built. Been out of circulation for awhile, therefore still a little conservative in my approach to engine building especally in street driven cars. 43 years of wrenching on aircraft, USAF and UAL makes me error in the side of caution, but hats off to those still active and keeping the spirit alive. But I'm still keeping that 467 of mine around 6000-6300 RPM though.
Al


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## Mr. P-Body (Jan 20, 2011)

Al,

Your engine, your rules. No problem here! My purpose here is simply to make all who read these threads aware of what's going on and what's available today, that wasn't just a few years ago. I also like to dispel myths and superstitions. Amazing to me how many folks drag up old issues and apply them to today (not speaking about your situation, just in general). 

When I tell folks about our packages and the power and revs they produce, I often get challenged. There are many less-than-scrupulous people out there that will become "nay-sayers" just to promote a product opposing OR to rationalize their choices, which may not be the better. They are known to "pad" the numbers or "reduce" the weight of their car, all to make it LOOK like they're approach is "better". They automatically apply that same mentality to our guys. For the record, we do NOT pad numbers, nor do we use creative math for weight, speed, etc. If anything, I err on the side of caution, too. If a car weighs 3,455, we usually say "3,500". 

Jim


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## BearGFR (Aug 25, 2008)

Mr. P-Body said:


> There are many less-than-scrupulous people out there that will become "nay-sayers" just to promote a product opposing OR to rationalize their choices, which may not be the better.


"Boy Howdy..." can I ever attest to that! Last year when I started in on my engine, I got "advice" that was all over the map. Take _any_ given approach or idea and you'll find at least one "faction" that's positively rabid about it being "the best", and you'll find at least one other "faction" that's just as rabid about it being "stupid and/or the worst". For awhile there I was driving myself nuts trying to figure out who to listen to. Somehow I got lucky and "hooked up" with Jim. (Dunno if I've ever told you or not, Jim, but what won me over was your willingness to give me real information that made sense without making it 'conditional' on me doing business with you.) 
He always says there "more than one way to skin the cat", which is true - and also a clue to the fact that he's telling the truth - but I'll tell you this: If he says it's going to rain, you'd best be grabbing your umbrella.

Bear


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## Mr. P-Body (Jan 20, 2011)

Bear,

I'm blushing... - 

Seriously, one of the reasons I started posting on Bill Boyle's site so many years ago, was all the BS I kept reading and hearing. I decided then, I would ALWAYS state my opinion, but temper it with reality. That can be a daunting task! When I make a mistake, it's a tough pill to swallow. It DOES happen. Just a few days ago, here, I said the headers wouldn't "fit", and was corrected. Now I KNOW! I'm not "learning impaired".

To all reading this:

When you're shopping for parts and services, some things to "raise the red flag"... 

"the ONLY way..." (probably the worst!)
"just as good only cheaper" (sometimes, but rarely)
"get away with" (blown engine looking to happen)
"I know more" "I've built more" "I've tested more" "I've tuned more"... A customer and his shop are a TEAM. There is no "I" in "team"... 
"Pie in the sky" If something sound to good to be "true", it probably is...

When someone bad-mouths a particular part, ASK "how many times?" This is especially true with internal engine parts. Say a crank "fails". Blame the crank? More often than not, when a cranks gets tore up, it is the victim, not the culprit. Loss of oil, not enough clearance, assembly errors, etc. This is a current "hot button" of mine... - Some really good parts get trashed by people supposedly "in the know", based on a single or onesy-twosy "incident". 

Watch the evolution. That is, if someone is selling a part or line of parts and touts them as "the best", but in a fwe weeks, they change suppliers, now the "new" stuff is "the best"... 

My biggest "pet peeve" is misleading advertising and selling based on that. 

Off soap box...

Jim


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## TK69tempest (Feb 28, 2011)

Thanks for all of the info and help. I've decided to go with the 400 and a TH350. The transmission shouldn't be hard to find and build, but now I have to find a good 400 block to work with - I had one lined up, but the deal fell through. What's a good choice of heads that won't need too much work at the shop?


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## Mr. P-Body (Jan 20, 2011)

Where are you located? I have some cores...

Heads that "don't need too much work" is "pot luck". At 40-plus years old, the odds of finding unmolested heads that are in real good shape will be a challenge. I have some "12s", but they're not going "cheap". 

IMO, you would be better off deciding which casting you want, and "build" a pair "to spec" for your performance goals. At least then, you know EXACTLY what's in them.

Jim


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## codywp (Apr 4, 2011)

get a 400 if we want ok gas and performance for a v8


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