Small Block & Big Block Chevy Specific - 400 Pontiac Engine

I just bought a $300 Camaro for my brother according to the old owner the motor is a 400 pontiac motor that he put in there. I was wondering if its a good motor. I was gonna rebuild it or was gonna swap for a 350. Is it worth rebuilding it or should I rebuild it.

What are the casting numbers on the heads (two or three digits on the center exhaust ports)?

The 400 Pontiac can be a great motor. The cool thing is that Pontiac used one block for all of it's motors from 350-455 :) Can you say bore and stroke it :devil: ??

personally I think the stock 400 small block is a dog. I say change it up!

400 is a great block to use. Post up the casting numbers so we can determine what it came from and so forth...

Derek

400 chevy and 400 pontiac are good blocks....the only one I would stay away from is the 400 chevy 4-bolt main because the webing on the main cap area is very thin...these are prone to breaking under hi-po applications.

The 400 Chevy engine is a small block, and a member of the 262/265/283/302/307/327/350/400 family. The 400 Pontiac engine is a big block, and is a member of the 287/326/350/389/400/421/428/455 family.
The Chevy 400 looks pretty much like any other small block Chevy, and the Pontiac 400 looks like any other Pontiac big block. I have owned and raced with both 400 small block Chevies, and 400 big block Pontiacs, and both can be built into real powerhouses.
If you have a 400 Pontiac, I wouldn't consider swapping it out unless you have a lot of Chevy parts laying around. I use to race with a 400 Pontiac that I had built up. I shifted at 6500 rpm every shift and raced the car sometimes at two to three tracks a week, for three years, and never hurt a part. Bob

You might want to check the casting number and find the application. I know the stock heads on some of those really sucked.

dump the pontiac and build a 350 chevy.its alot cheaper.just built a pontiac motor for my buddys 77 trans am and it was a pricey pain in the a$$ to complete and still isnt running yet due to lack of funds.but on the other side i built a 355 for my 85 camaro no problems that ran 11.80s and didnt spend more than 4000 grand on motor tranny and car,trans am will probably see low 13 high 12s and hes already at around $5000 and still not done yet.but its your stuff, your money,do what you want.

The 400 Pontiac engine is a big block, and is a member of the 287/326/350/389/400/421/428/455 family.

Isn't big block a term to distinguish only chevy motors?

Isn't big block a term to distinguish only chevy motors?

umm no...thats kind of funny ...i could distinguish a big block from a small block in middle school...anyways i personally have a 71 formula firebird with a pontiac 400 its a strong motor and would recommend you sell it to a pontiac guy and but a chevy engine for the camaro....but other than that it is a good engine to mod :)

The Ponchos were always classed as Large Journal and small journal due to the cranks. The 326-400 were SJ where the 421-455 were LJ. They weren't classed as big and small blocks due to they being all the same dimenionally until the 301 came out in 79.
Also, Chevy sometimes marketed the 402BBC as a 400 in the "Big Car" (Impalas, Caprices, etc.)
Virgil