What years was this motor offered in the T/A's ? Also how good of a motor was it REALLY ? I hear alot of people having 400's in there cars but not alot of 455's. Are they just pretty rare now or what ? Can the 455 be built up nice with aftermarket support and does it respond well to mods ? Thanks!!

 

Well, firstly the 455 isn't a big block...same block size as a 350 or a 400. Infact it's a 400 with a quarter inch more stroke and 0.03 inch more bore. That said the motor is a BEAST, tons of torque. You can get three different aftermarket heads for it, but most people go for Edelbrock heads. Anyways, even car-craft gets those motors in the 500hp+ range with no real work.

 

So you can build this motor up with a 400 block is that correct ? If so what are the best year for the 70's body style T/A ? I'm thinking about getting out of the 4th Gen cars and doing something a little different so I'm just starting to learn about these cars. I really want to do a fuel injected 455 or possibly a carbed set up (which ever will be faster). It will be a track only car with very little weekend driving. Any help about these cars would be appreciated.

 

Yes you can build the 400 to 455, very common mod. You need to get a stroker kit, it comes with a new crank, new rods, new pistons. Basically the stuff you'd need for a build up anyways... plus you get the extra stroke. You really won't see too much different in an NA carb'd VS injected set-up. The performance diff will be minimal...

 

76 was the last year a 455 was offered in a T/A. Check out Jim Butler Performance, and pointiacdude for some of the more common kits. You can build a 400 block to 467 (IIRC) cubes.

 

Remember that the Pontiac 455 isn't the only 455 that will fit. You can also get an Olds 455 and swap it in there as well. You would only need to get the 403 motor mounts for it to fit. The Olds motors are big blocks and are torque monsters. Many people also use the Edlebrock heads with these as well.

 

GM made hundreds of thousands of Pontiac 455's, then put them into everything from trans ams to bonnevilles. I'd recommend you check out some Pontiac sites for more hardcore info. There's also a magazine, High Performance Pontiac, published by JHS Publications of Hackensack, NJ (201-488-7171) [Unk if its still in publication]. They might even have a website. In getting this info for you, I pulled a 1988 copy of the magazine out. There's an entire article about building the 400 into a 455. It appears to be a fairly simple process, turn the 455 crank bearings down to 3", 400 rods, 455 pistons/rings.

 

Thanks arocars, very helpfull info and I appreciate it very much.

 

honestly,if you are starting from scratch and arent really needing a pontiac motor for your bird id go with a tried and true big block chevy.theyre just about equal in torque and horsepower and the chevy is shown to be reliable as hell but the diff is much much cheaper to buid than a pontiac...period..look at the parts in any catalog...pontiac stuff can be 2 to 3 times higher for the same part and why pay for that if you dont need a pontiac motor.im assuming you just want to haul ***

 

That article was probably written before stroker cranks were available.. as I would think the labour would negate using a 455 crank.
A big block chevy is easier... and cheaper.

 

actually my buddy did a 400 pontiac stroker,omes out to 461,its suppose to be the hot set upfor pontiacs but i don think there wa sany additional labor needed,but like i stated everythingis more money.

 

News flash, a BBC is NOT cheaper to build than a Pontiac 455! A sbc is definitely cheaper but not a bbc. Here are a few price comparisons:

(Jeg's prices)
Edelbrock RPM heads $849 for Pontiac (60579), $859 for BBC (60459)

Edelbrock RPM intake $194 for Pontiac (7156), $193 for BBC (7161) or $229 for the Air-gap version (which is more like the Poncho version)

Edelbrock RPM cam and lifter kit $187 for Pontiac (7157), $192 for BBC (7162)

Speed-Pro forged .030 flat-top pistons $38 for Pontiac (L2359F30) and $46 for BBC (L2377F30)

Car Craft did a build up of all the big inch factory muscle car engines a few years back and made this handy chart that shows price per performance.