# 455 build questions/ideas/pointers/help etc



## Onebrokegoat (Sep 27, 2018)

(It was pointed out to me that I posted this a day or so ago in the wrong GTO sub. My bad. Maybe it’ll get a bit more traction with you guys than from the LS guys lol.)

Getting ready to put my 67 in a shop and have the 455(out of a 72 something) built. The only part of this that I will be personally doing is loading it on the trailer and pulling it off at the shop. HP means 0 to me. The car never sees 75mph, let alone faster. Im
fine if the speedo tops out at 90. I like a lot of torque, and low gearing, to roast the tires off, show my a** as I’m pulling out and then promptly cruise straight over to the tire shop.

It has the th350 and eventually will be upgraded to the 200r4 after the engine build and $$$ is saved. I’ve converted it over to a Holley sniper EFI, serpentine belt, power disc breaks, and fully bagged it. It’s purely a cruiser. There’s nothing original about the car. Different motor, Chevy 12 bolt rear, all the things I’ve done to it, gold interior converted to black. It’s not really a survivor and it’s way to far gone to be a restoration candidate. It’s just a hot rod.

I want it to have bomb proof internals. Overbuild and under utilize. Forged crank, forged pistons etc... I want it to be reliable enough that I’m confident in my wife and toddler heading across the Smokey’s in it to rod run in Pigeon Forge,TN and back while I’m at work. I want a stump puller, lopey cam that screams “listen to me I’m cammed!” And sounds really awesome when I pull in somewhere to turn heads and get people looking. This is the part I really don’t know how much you can balance with drivability and reliability(remember it has EFI and power disc so it needs usable vacuum boost)

I don’t care about hp at 5500 rpm. I don’t care for the car to ever see 75 mph. I don’t need bragging rights from a Dyno sheet.

I want it to be reliable, look good and sound better.

Budget I’d like to stay at or under 7500$, but I can go as high as say 10 if need be. Higher than that I’ll just buy a Butler or Nightmare drop in.

What kind of cams should I be looking at so when I sit down with the builder I have an idea of the direction we should go? I know what lift and duration are but not really what the numbers mean and how to read them.

I talked with him briefly and he basically said hydraulic cam, roller rockers, probably aluminum heads(recommendations?), but never got into the internals. Cam brands? Upper kits and lower rotating assembly kit recommendations? Through butler the kits are about 5k for both, but I kinda figure you can piece it together cheaper?? Plus I don’t know what kind of end game those kits produce.

Would either a big bore or stroker kit be more beneficial over the other for low end torque and ultimately reliability and especially drivability. Like I said, my wife takes our 4 year old and cruises without me. What you send your wife and daughter out in?

Any help would be greatly appreciated. I know it a super long shot, but has anyone ever dealt with Ben Barnes Performance in Asheville Nc? Or recommend a builder in Asheville, Charlotte, Greensboro, Atanta, Knoxville, Bristol area?


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## Lemans guy (Oct 14, 2014)

That sounds like my 66 Lemans. By the way Butler will work with you thru any stage of your build. So I had a 400 block took it to Butler’s it was cracked. So they supplied me a 400 1968 block and cut and race prepped and zero decked the block. They also installed the cam bearings. I bought a stroked kit from them Eagle with dished pistons.

My friend, a super Pontiac Builder, and I put it together from there. We used flat tap pet cam not a roller. The Compession we shot for came out at about 9.3. We put on cast iron heads.
With the smaller valves. Had the head reworked, valves cut etc.

Called Lunati Cams near Memphis told Mike there what I wanted, like you torque low a cruiser, nice lope did not care about going fast from 90 to 100 mph. Told him I was running a .308 12 bolt rear, also have a gear vendors overdrive.

Lunati cut me a custom cam for what I wanted for $50 more. So if the cams are about $150 a custom cut was $200. I also use Harland sharp roller rockers, and Butlers beefed up just a bit oil pump.

I also have a serpentine belt, a quick fuel 780 CFM Vac secondary carb and a th350 trans, beefed up with a ratchet diode to take plenty of torque.

It is a great cruiser, fun reliable and strong, but the power band is low. Agouti won’t beat some guy with large valves and ported heads and 3.73 gears....

Talk with Butler they may help you do some of your build. Their machine shop is like a hospital it is so clean, they are great folks, and have a fully stocked shop right there in Lawrenceburg, Tennessee.

Make sure you put a strong mini starter on it. I recommend RobbMC Starters and get a strong battery and alt and keep them in good shape!

Sounds like some fun on the way!


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## PontiacJim (Dec 29, 2012)

OK, I'll post my suggestions again based on a nice running, peppy engine, that is comfortable to drive and not the street/strip HP/TQ most want. Keep in mind these are my suggestions and my opinion based on what I might do. Your machinist/engine builder will have their opinion, but you may also have to hold your ground if you feel you want to use a specific item or go a different route than they advise. Remember, they work for you, not the other way around.

455 block - hot tanked/cleaned, magnafluxed for cracks - magnaflux all used parts for cracks which most every machine shop will do. You then want your machinist to check the deck for straightness/squareness. He may have to deck/cut the surface a little to get things right, or not as it may be good as is. No need to spend $extra if not needed.

Then you want him to measure the piston pin height and how far down in the cylinder bore this puts your piston. Pontiac typically can be .010" - .020" from the top of the block deck to the top of the piston. You want to know this number when ordering your custom Ross pistons, and here is why - Quench/Squish area above the piston.

Some people/shops will want to cut the deck down to match the top of the piston, called "zero decking" the block. What you are after is trying to get an effective Quench/Squish measurement, that little space between the top of the flat area found on the piston (not the dish or valve reliefs because they are sunk in) and the bottom of the flat area of the head (not the combustion chamber). That little space between the flat areas should be around .040" depending on how deep the piston is in the hole and the compressed thickness of your head gasket. This area, and getting it right, can greatly help prevent detonation, cool off the fuel/air mixture, and even reduce timing settings.

So most favor cutting the block to "zero deck" which puts the top of the piston even with the block leaving a "zero" measurement of the piston down in the hole. So this makes it real easy to purchase/use the Felpro head gaskets that come in a complete gasket kit as they compress to about .039" and gives you what you want.

Option #2 is by using the pin height supplied by your machinist, you can actually move the piston pin height lower when the Ross piston is machined, thus moving the piston higher up into the cylinder and achieving a "zero deck" without having to mill your engine. As an example, if the factory piston with its pin height measured .020" in the hole, you new piston would have the piston pin moved .020" lower to push the piston higher up into the bore and give you that "zero deck" application. Then the Felpro .039" gasket does as above.

Option #3, and what I did with my 455 build, was to use a thinner head gasket to get a better Quench/Squish. My KB pistons are .020" down in the cylinders. So I went with a pair of Cometic .027" thick head gaskets which obviously are thinner than the .039" Felpros. They cost more as well at $100 each when I bought mine. So my Quench/Squish is found as .020" + .027" = .047". Slightly more than the preferred .040", but my machinist said .040" - .045" is what he uses and .047" was just fine. You have to take into account that heat expands metal and that .047" will tighten up a little and if I run a shot of nitrous, the cylinder hear really shoots up, so the piston will expand more and I'll be perfect for the nitrous use.

You can keep your stock crank which is a good piece as I explained to you earlier and then get forged rods/pistons to match your stock crank's stroke - UNLESS you feel the need to use a *stroker kit *for more cubic inches. Not a bad option as you can get a little more stroke which is nominal, the forged rod/pistons, rings, bearings, and balanced. This may be your best bang for your buck when you start adding up prices for individual parts, ie pistons, rings, rod, bearings, etc..

So from your 3 options above in acheiving a good Quench/Squish, if your machinist wants to move the piston pin, you want to let Butler know this and what amount so it can be added to the Ross piston as well as the CC's of your dish in the piston to arrive at a pump friendly 9.0-9.3 compression..

But, here is what I would want to change, and you could ask Butler their opinion of course. I would want the 3/4 Groove main bearings if they don't already supply those.

Above you get all new parts.

However, before you go an order pistons, you need to know what the CC's are of the combustion chamber of the heads you use, iron or aluminum. If you go aluminum, they already have their CC's spec. If you go iron heads, then I would do a complete rebuild and then have your machinist check 1 chamber to see what the CC's are. Once known, now you can determine how much dish will be needed in the piston tops to get your to a 9.0-9.3 compression.

I prefer iron heads for a number of reasons. First, same material as the block and less moving around between the head & block due to different rates of expansion. The Cometic gaskets are really better here as they are MLS (multi-layer) and allow for movement due to these expansions & contractions. Iron heads are "Pontiac" and not aftermarket. I pop my hood, and its Pontiac. 

I won't get into what should be done, or your options, with the iron heads when rebuilding until you decide if you are going iron or aluminum. Cost is a factor. And as I pointed out in your earlier post, go 1 point more in compression if using aluminum heads. With iron heads, you do want a head having the larger 2.11" intake valves and screw-in rocker arm studs. Small valves will work on a street engine, but you will give up performance, RPM, and be limited to cam lift choices due to press-in studs.

Aluminum heads will flow more CFM's out of the box, but with a Pontiac head, you can get good numbers with a little basic work. You really want to keep the fuel/air velocity up high and this is what makes the engine really snappy when you hit the gas. Now the smaller CFM flow of an iron head versus the aftermarket aluminum head may be the choke point that limits your effective RPM range, but for a street engine, the difference between 5,200 and 5,800 really isn't an issue when you are looking for a driver - and don't think this means tires won't be smoking either! LOL

So cam choice has to be matched to your shortblock specs, ie compression, head choice, converter stall, trans gearing, & rear end gearing. So another item I'll leave open for now depending if you select a roller cam or flat tappet cam, but a basic cam might be 112-114 LSA, 270-290 duration, .500"-.520" valve lift which is not going too crazy on a street 455. 

Purchase the Butler Pro series 60PSI oil pump and a hardened oil pump shaft. These are blueprinted and altered to deliver more volume, not pressure.

Use the Best brand rope/graphite rear main seal as it seems to prove to have less issues with any future leakage. You can get the Viton 2-piece seal, and I have used it with no issues, but the Best seal seems to be favored in producing better results where if the Viton seal is not perfectly applied and fitted, you may have leaks.

Your oil pan can be re-used if good, but they do make an aftermarket replacement. I prefer to use an oil pan having the factory oil baffle in it which is a plus if you like to nail the gas and show off a bit. You can also go aftermarket like Canton which will have baffles and more capacity. Your pan may or may not have the factory oil baffle. 

Intake choice is open, but the factory Q-jet and a Q-jet carb can't be beat. The aluminum intakes are lighter, but I don't think that should be a concern. If you really want dependability and hassle free carb issues, then an aftermarket EFI type carb is the way to go. It will require some changes in your fuel system such as the pump and pick-up and the best route is to purchase a new gas tank that incorporates and used the electric fuel pump. This can eliminate the hot start problems many experience through fuel percolation and fuel evaporation due to the ethanol laced gas. They have a few set-up that look like a carb and hook-up with the car's throttle linkages, and under and air cleaner, you can't tell.

You will want a new harmonic balancer to replace the old & unsafe factory unit of almost 40 years.

Get a new water pump and water pump stainless steel divider and rubber inserts. Clearance the divider to the water pump impeller. I like a 160 degree T-stat, but a 180 may be better for your use. A cooler running engine also minimizes any chance of detonation.

For exhaust manifolds, the aftermarket RA cast iron manifolds are best. Stay away from headers. Get the cast iron RA exhaust manifolds with the mandrel bent head pipes as they offer a smooth turn to aid in exhaust flow.


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## Onebrokegoat (Sep 27, 2018)

PontiacJim said:


> OK, I'll post my suggestions again based on a nice running, peppy engine, that is comfortable to drive and not the street/strip HP/TQ most want. Keep in mind these are my suggestions and my opinion based on what I might do. Your machinist/engine builder will have their opinion, but you may also have to hold your ground if you feel you want to use a specific item or go a different route than they advise. Remember, they work for you, not the other way around.
> 
> 455 block - hot tanked/cleaned, magnafluxed for cracks - magnaflux all used parts for cracks which most every machine shop will do. You then want your machinist to check the deck for straightness/squareness. He may have to deck/cut the surface a little to get things right, or not as it may be good as is. No need to spend $extra if not needed.
> 
> ...


WOW! Thank you. That is a LOT to take in, and I have a lot of reading to do in order to really comprehend 75% of that, but thank you. That’ll give me somewhere to start and some basic knowledge when I walk in there.

I’ve already done the harmonic balancer, full EFI with new tank/in tank pump, high flow water pump, 180 thermo, dual electric pullers with electric pusher, 3 core aluminum rad, mini torque starter.


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## Lemans guy (Oct 14, 2014)

Solid advice from PJ, all those things matter, go slow and enjoy the trip as well.


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