Pontiac muscle V8's (a question about differences in them)

[Ghoste]

I know some of you are Pontiac fans as well so maybe you can help me with something.  My understanding is that all of the Pontiac V8's from the muscle era are essentially the same as far as the block goes and that CID is changed largely through a crank swap?  Is this true?  If so, how do you determine what size is actually in your car?  An engine stamp?

[Budnicks]

I know some of you are Pontiac fans as well so maybe you can help me with something.  My understanding is that all of the Pontiac V8's from the muscle era are essentially the same as far as the block goes and that CID is changed largely through a crank swap?  Is this true?  If so, how do you determine what size is actually in your car?  An engine stamp?

I think your correct, allot of the parts are interchangeable, but I don't remeber which ones & won't sware by it, I haven't delt with real Pontiacs for 30+ years now, the newer Pontiacs are kind of just dressed up Chevy now, or were I shoud say... Try going to www.highperformancepontiac.com , forum , they will not steer you wrong, some good guys over there too...

[Ghoste]

Do you know if the serial number stamping can be seen with the timing chain cover still in place or is it behind that?

[no318]

Serial # can be seen along the front of the block near the timing cover.  It is not covered by the timing cover.  There are some differences in blocks and casting #'s.  389/400 are pretty similar.  455 has a larger main bearing so has its own block. 

What are you trying to do?  Swap an engine or determine originality of something?  There are some motor mount boss issues if swapping early and later pontiac 400's.

[Ghoste]

Determining originality.

[no318]

That helps.  THere is a casting # and date code for the block on the top rear by the bellhousing (behind the dist.).  That will get you going.  Then there is a 2 digit code on the front of the engine, below the pass. side head, that breaks down to HP rating/auto or man. trans, etc.  The VIN is along the pass. side of the timing cover below the water pump.  This is for late 60's-late 70's. 

[moparstuart]

 so is there not really a big block and small block

[Ghoste]

Not really.  There is a larger main journal block and a regular one but beyond that the block architecture is nearly identical as I understand it.

[no318]

Not really.  There is a larger main journal block and a regular one but beyond that the block architecture is nearly identical as I understand it.

That is correct other than the late 301.  It had a short deck height and narrow intake.  (similar to a 440 vs. a 383/400).  All other pontiac blocks were the same.

[471_Magnum]

Yep. Bore spacing and deck height are the same on all but the 301, which has a shorter deck. 455s have the bigger mains.

[Ghoste]

Is the 301 considered a "Canadian" block?  I have heard something about a Candian one that is basically like a 350 Chev?

[A383Wing]

That helps.  THere is a casting # and date code for the block on the top rear by the bellhousing (behind the dist.).  That will get you going.  Then there is a 2 digit code on the front of the engine, below the pass. side head, that breaks down to HP rating/auto or man. trans, etc.  The VIN is along the pass. side of the timing cover below the water pump.  This is for late 60's-late 70's. 

yup...that's how I checked out my 455 in my Pontiac...plus I got the build sheet and checked my starter, alternator, & distributor and they were still all OE as well

of course I knew they were..my Grandville was my dad's and it only has 55,000 miles

Bryan

[471_Magnum]

301s were thin wall with a very weak bottom end. It's claim to fame was light weight. Don't know nothing about a Canadian one, but supposedly the turbo 301s were beefier.

That being said, I tried my best to blow up the one on in Mom's '79 Grand LeMans Safari wagon... and failed.

[Cooter]

"Imma Test pilot for the Navy see. I test fly planes that are top secret. That's why I Bought this car with the 455 with Ram Air, and beefed lower end"...

"GTO" from Two Lane Black Top.

[b5blue]

 '55-'81  Pontiac V8's 265, 287, 301, 303, 316, 326, 347, 350, 370, 389, 400, 421, 428 and 455! All built on same 4.26 inch bore spacing and block architecture, that's 14 displacements.
Then there is the GM B.O.P. V8 (Buick, Oldsmobile, Pontiac) from '61-'80 in 215, 300, 340 and 350.
So there are 2 "type" engines available in certain years for Pontiac. For mind blowing 18 possible, not counting the years Chevrolet engines were installed in non Chevrolet cars in the 70's (Remember all the fuss!) engines depending on year and model from '55 to '81.
  Then from '81 up you have the SBC in at least the 305 and 350 form putting the total at no less than 20?