Is a 1967 pontiac firebird 400 engine a big block or a small block?

all 350-455 pontiacs are BIG blocks. Gotta love pontiacs!

Is a 1967 pontiac firebird 400 engine a big block or a small block?

As Vpap1 said, they are big (and heavy). They are much heavier than the SBC even though the first one (1955, 287 cu.in.) were only slightly larger than the 1955 SBC (265 cu. in.) The difference is that there was plenty of 'meat' in that 287 to go larger (455). And, Chevy went for RPM's while Pontiac went for torque.

They were never classified as being a big block or small block, since they were all the same external size.

Did you know that Pontiac had a limited run of V8 engines in 1932?
And that Chevrolet had a V8 in 1917?

I have always wanted a PONCHO V-8 in a 3rd gen F-body - Any one got one ? I'm almost sure hooker had headers at one time.

I asked this before and NO not a chevy 305 or 350- that is NOT a PONTIAC engine - 389-400-421-428-455