Both are nice engines. I recently picked up a 454 at a very good price and was gonna shoehorn that into my 79 TA. But then I started considering a 455. I'm kinda stumped on what to choose. I havn't heard alot about the 455's. If anyone could list pros/cons, that would greatly help.

Thanks
Lars

Both are nice engines. I recently picked up a 454 at a very good price and was gonna shoehorn that into my 79 TA. But then I started considering a 455. I'm kinda stumped on what to choose. I havn't heard alot about the 455's. If anyone could list pros/cons, that would greatly help.

Thanks
Lars

Well-
the 455 is a Pontiac engine.
To put anything but a Pontiac engine in a Pontiac is just blasphemy!!
They are great engines,and have plenty of torque.They don't rev high like a Chevy-they weren't designed to.They don't need to,either.You can get all the horsepower and torque you will ever need with a 455.
They were only made for about 7 years,so they are not near as common as any Chevy.

go with a 455 whenever i se a pontiac with a chevy motor in it I lose all intrest that and when you pop the hood you can say its a 350/389/400ect with a 454 everyone knows what a 454 looks like and with a 454 it's like it not a pontiac anymore but a chevy pontiac all the way

the differance is COST and DURIBILITY of parts!!
A lot more reliable HP can be made with the BBC.All the pissing and moaning by the purist cant deny. High HP requires a good crank aint gonna get that in a 455. Unles of course you go with a billit crank. By the time you shell out $3000 for a billit 455 crank you could have built a COMPLETE short block BBC. Some here will complain that you gotta rev a chevy high to get power. thats BS. I only spin my 496 to 6300 rpms. Not only that i am still running a solid flat lifter cam. No need to spend the extra money for a roller. Also no lifter bore brakage either.
its all bout the Dollars and Cents basically less expensive makes COMMON SENSE!!!!!
Come on over to the dark side just make sure you have plenty of kleenex for the whiners!!

Ignorance states that a 454 is a better engine than a 455. The crank on a 455 is bulletproof, ask around, you'll see the light.

cast crank is fine to a point. that i will agree. but if you think it will last in a Real high HP application . you gotta be smoking crack cause that what cast cranks do they crack under heavy load. Any cast crank will no matter what it is in. Chevy, ford , mopar ,and pontiac it dont matter a cast crank is INFERIOR to a FORGED one. Bullet proof yes but the last time I saw a motor blow it went off like a bomb not a gun!!!!
Ignorance also assumes something from nothing. Where did i say it was better. If you would stop being so ignorant yourself and reread the post i said it is more practical.

I didn't state you were ignorant. I was stating that off the line the 455 would probably be a better motor. I do agree with you on the cheaper for parts idea. Parts are killer when you start to look at 3000 dollar cranks, 2100 dollar heads, thats a problem I am dealing with on my 455. It's all opinion. I know you can get a 454 to a 496 and make worlds of hp, my friend is doing that with a truck of his. I just dislike a Chevy in a Pontiac, but it is your car, and to each his own. Oh one more thing, take a built 454 and compete with one of these racers on this forum with a built 455 and lemme know who wins.

You use the word "ignorant" quite freely.

The truth is, if you want to ruin perfectly good Pontiac with a chevy truck engine, that certainly is you right.

Only 640 hp out of a 496?

Have a nice day,

Jim

Go with the 455. Your car is HEAVY. The 455 will produce a nice flat torque curve and produce more torque than the 454 in most cases. Also, BBC parts are cheaper but not by much. Look in summit and jegs. The small block stuff is way cheaper, not big block. If it is a street car your building, get jim hands book, it is a useful guild to Pontiac power, and go with the 455 or better yet, a 474!

Mo,

Great reply!

That says it all.

Jim

if these engines are relatively stock the pontiac will get better fuel milage than a chevy every time.

also the pontiac's components are made from better materials. ask any engine machinist, they'll agree with this.

mike

As a builder of all things automotive engine..., I must agree with much of what has been said here.
There is little doubt, BBC is one of the finest powerplants ever made by anyone, especially for racing applications. It's not without drawbacks. It is very heavy. By using aluminum heads, one can shed a hundred pounds or so. But, aluminum heads for a BBC are MORE money than for a Pontiac (for good ones, at least). Also, as previously stated, BBC is more money than SBC, by a wide margin.
If your car is meant to handle like a T/A, use the Pontiac. You will maintain the factory "balance" in the chassis. A BBC would make it nose-heavy.
While peer pressure may or may not be an issue with you personally, what was said about being an "outcast" is true, if you look under the hood of an old Poncho and see a Chevy.
For street driving and occasional racing, the Pontiac is every bit as potent as the BBC, Perhaps moreso in a heavy car.
There are those that believe you can't make ANYTHING fast without a Chevy motor. This falls under the heading of "myth and superstition". Only a fool would say Chevy isn't a good engine, but the same fool might say the Pontiac's no good, as well.
As for the debate on cast versus forged cranks, it's absolutely true. Once you pass 700 horsepower, a stock crank can be a liability. Under that, the Pontiac is much stronger than the 454 cast crank. Chevy engines need the better cranks at a lower level.

Wow, thanks guys! I think after whats been said here, I'm gonna go with a 455. Im only really looking for about 350-400 horse tops. Any more then that would be overkill for my use for this car. With that said. Can anyone recommend me a type of 455 to use. And some decent parts to buy. I'm willing to put about 3000 into it. I'll put more in later but the car has other needs.

So basically im looking for the best parts I can get in the 3000 range to get a pretty nice 455 going. Any recommendations?

Thanks again guys!
Lars

Slinky, Don't worry about the cast Pontiac crank. I run a 474 (4.25" stroke) that I spin 7100 with a factory crank and it makes 848hp at the flywheel. I feel that problems with Pontiac cranks are due to insufficient oiling. I run a Titan pump, but think that the oiling mods shown in another thread would accomplish th same results without the expence of a billet pump. For the street or street/strip, I don't even think that those mods need to be done. Just be sure all your clearances are right on and you have no flow restrictions.

I believe that the best 455's can be found from 1970-74 after that i heard the blocks lost quality or something. If you have 3000 bucks you should probably fork out 1500 or whatever it takes to get a runner, that way you don't have to go through as many problems. Right now i have a '74 YY with 4X heads in my 68 GTO and it runs fantastic. As for parts if you only want 350-400 horespower you could use the Edelbrock Performer intake, Performer Plus cam and lifters, go with roller rockers (i'm going to use Scorpions), and i use a QJet up top because i feel they flow the best. I'm also looking into Keith Black Forged pistons. Oh and get your intake port matched, it helps. Hope that helps, your goina have fun!

Slinky, glad to hear your choice. You shouldn't have any issues with that power level. Get Jim Hands Book if you didn't already, from PY of course, it has some very useful info. The 455/6X head combo is very popular and a reliable performer with good streetability. Put your money in the heads and the power will follow. Good Luck!

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> Im only really looking for about 350-400 horse tops. Any more then that would be overkill <HR></BLOCKQUOTE>If it were me I would install a 400. I know your looking at a 455, but, a stroked 400 would give you those #'s real easy. 400 blocks are cheaper and much eaiser to find. Plus alot of builders offer a complete stroker kit to make your build pretty simple. Just something else to think about.

great choice check out the performance parts and see if anyone has a 400/455 longblock you can buy

the weight difference between a 454 and a 45 is probably so minor it would never matter. a 454 weighs 675lbs...an 389 weighs 650 and i would say a 455 weighs even more...so where's the big issue with weight? Not to mention a 79 T/A isn't going to have the best of weight dist anyway, it's always going to nose heavy. A total rebuild kit from Northern auto, for a 454(minus crank) ranges from $357 to $524(for late model engines), a 455 rebuild kit(minus crank) is 543. Svaings?
I say put whatever you have in the car, or whatever you want. The only difference is with the pontiac you won't have to swap trannies if your bellhousing bolt pattern is different. Another problem could be height differences between the 454 and 455...i can't find any info on that.