[lou4612]

Hey guys I just bought a 1981 Trans Am.
The owner says the engine is a 455 that was installed before he bought it!
How do I make sure..its a 455 and not a built 400!
The car is isanely fast..waaay faster than my 2000 LS1 Z28!
I drives and sounds awesome..for the money I payed for it!
I dont know the specs on the engine...but for some reason the top end power on this baby is insane it just wants to keep pulling and pulling!

He also threw in a second set of T Tops..that I may put up for sale!

["QUICK-SILVER"]

Look on the drivers side of the block, up close to the front, below head going down towards oil pan. On 350s, 400s and 455s, the numbers are cast (raised up).
From the top, pretty easy to see with flashlight and mirror.

Not unusual to hear stories about Pontiacs that run like that. "insanely fast"
Be careful till you get use to it.

With some more time, get some casting numbers and can tell more about what you've got.

[mzbk2l]

Welcome, Lou! Looks like you've picked up a fun ride!

Here's a thread that had some useful info and a couple of pictures:

http://forums.maxperformanceinc.com/...d.php?t=522719

You can also find the date code information from the back of the block (near the distributor), and the two-letter code stamped in the front of the block, below the passenger side head. Post those two pieces of info here and someone will tell you what block you've got.

What heads are on it? (The two or three digits cast into the heads on the center two exhaust ports - 6X or 670 or 17, etc.)

[2manyT/A'S]

Just remember to LIFT your right foot BEFORE 5500 RPM.

Pontiacs DO NOT rev like SBC's & WILL explode.(grab another gear & stay in the power band)

[ve3wireless]

I know this isn't much, for sure, but back in '77 - '78, a dead giveaway that betrayed the presence of an honest-to-goodness factory-tricked Pontiac "T/A 6.6" engine under the hood (as opposed to a "regular" 400), was the chromed valve covers...

Of course, the ones on your car could well have been "swapped" out of a T/A 6.6 & placed atop the 455 strictly for looks by someone before...who knows?

It sounds like a nice car --- enjoy the ride!

Eddy

[lou4612]

Damn car started knocking today..or valves need adjusting!
Car is now for sale!

[b-man]

Originally Posted by lou4612

Damn car started knocking today..or valves need adjusting!
Car is now for sale!

If you revved it like an LS1 engine then you probably have a bad rod bearing that's causing the knocking, you just can't rev-up a Pontiac V8 (especially a 455) like you would a smaller Chevy-derived engine.

If it's now for sale please post an ad in the 'Firebirds for sale' classifieds forum.

Look here behind the fuel pump on the side of your block to see if it's a 400 or 455, your future buyer will surely want to know which one it is:

[lou4612]

Originally Posted by b-man

If you revved it like an LS1 engine then you probably have a bad rod bearing that's causing the knocking, you just can't rev-up a Pontiac V8 (especially a 455) like you would a smaller Chevy-derived engine.

If it's now for sale please post an ad in the 'Firebirds for sale' classifieds forum.

Look here behind the fuel pump on the side of your block to see if it's a 400 or 455, your future buyer will surely want to know which one it is:

No I didnt over rev it.
Also..is that 455 code at the bottom of th eblock..because my longtube headers cover alot of area!

[b-man]

The picture shows it pretty close to the front of the block on the side, just a couple of inches above the oil pan flange. Your headers shouldn't cover it up, my headers are full-length and you can see it pretty clearly.