If you mean the difference between the Pontiac 400 and 455....the differences are the bore size, the crank stroke length, and the main bearing journals. All are bigger on the 455. However, there is also a small block Chevy 400....which has nothing the same as the other two. The Pontiac 400 has a bore of 4.12, stroke 3.75 and 3" main journals. The 455 has a bore of 4.151, stroke of 4.21, and 3.25" main journals.
Depends on which Pontiac engine you are referring to. Any GM engine 400 cubic inches and under are considered a small block with two exceptions. The 396 is a big block and there were certain 400's that are big blocks. Two versions of the 400 were built.WRONG. All Pontiacs from 326-455 are the same size block externally. The only major difference is that the 326, 350, 389, and 400 have a 3" main bearing size. The 421, 428, and 455 are 3.25" mains. Now...if you are talking about comparing a Pontiac block to say a Chevy block....the Pontiac is larger than a small block and slightly smaller than a big block.
70s
Couldn't find that number at Mortec, but 3951509 is a 400. hth
shiping weight is 400, so probaly 370 without packaging materiels
About 20hp.
alot 283 , 302, 305, , 327, 350, 400 Pontiac which is still gm had 301 and 455 big block...........Chevy LS series motors are the best all aluminum.....STOCK roller motors and what not multiport fuel injection bolt on power mods that are stock on corvetts for ls1 and 2 motors easy power by ordering a gm part
The most popular engine was the 400. However, in those days, you didn't have to buy a cookie cutter car like you do now. You could pick and choose just about any option you desired. So I am sure there are '69 428 equipped GTOs out there. GM had a self imposed 400 ci limit for intermediates. It was lifted in 1970 and they started to use the 455. Prior to 1970 the 428 was only used in full size models.
LS1 is a GM engine, Z/28 is (was) an option package on Camaros.
In GM trucks or new GM cars, the 8th digit of the VIN # is the Engine.
Chevrolet's used a different bolt pattern from other GM's. An adapter would be required.
GM?
That is 1.764 cups