So I bought my 65 Cutlass a few years back and have not done much to it other than gather parts. I was told it had the 330 replaced by a 425.
I was new to Olds and never checked it. Didn't know how back then. No need as I was going to build up a 455 for it anyway. Well I'm leaning over the fender yesterday and just happened to look at the cylinder head and see a 4 cast on the corner. WTH?
Caveat Emptor.

Time to study SBO to BBO swap.

 

Never believe what you are told, are you sure it is a 425 and not a SB Olds?

 

I really don't know what it is. I suspect based on the heads I have a 330.
hence the SBO to BBO swap phrase.

I'll look closer when I pull it.

 

Whats the numbers on the block by the oil fill tube ?

 

A photo or two will solve this mystery.

- Eric

 

ah yes, the 65 330 and 425 had the same block numbers behind the oil fill tube. why? i couldnt fathom why. a few car ads with old guys thought they had original factory 425 cutlass's