Was the 389 pontiac engine a small or big block?

Question

Was the 389 pontiac engine a small or big block?

Answer 1

Pontiac like Chevrolet also introduced it's engine family 'way back in '55.  Although there were many updates over the years, all the engines except for the 301 and the 265 use the same deck height, and since the smaller 301 and 265 blocks are terrible for performance usage, most enthusiasts will say that Pontiac does not have a "big block" or "small-block" engine division, instead, the division between "big" and "small" is not the block size, it is in the size of the crankshaft main bearings:  All engines 400 cid and under use 3" (early engines have even smaller) main bearings.  All engines larger than 400 cid (that is, 421, 428, and 455) use 3 1/4" main bearings.  The Pontiac engine is considered by many to be the most performance-oriented of the non-Chevy designs.  This would be disputed by fans of the Buick and Olds engines, who rightfully point out the cast iron (not forged steel) connecting rods used in almost all Pontiac V-8s since the early '60's.  Still, it was Pontiac, not Buick or Olds that won many NASCAR victories in the early '60's.  An interesting variation of the Pontiac V-8 is the slant-four "half-of-a-389" used in Tempests

Answer 2

It is neither.   Pontiac V-8 blocks were all externally the same size.   The internals is where the differences were.

You can't tell the difference from a 389, 428 or 455 by opening the hood and looking at one.  

The answer above saying "small block" is wrong, too.   The link the guy provided does not use that term anywhere.  

Answer 3

I want to show you this because previous yahoo answers and those that are googled are wrong.  Small block.

http://en.wikipedia.org/wiki/Pontiac_V8_...

Answer 4

it was a big block even though they didnt have though all pontiac at that time were the same size. it is the size of a big block chevy

Answer 5

The short answer is no.