There were 318s the a came with a Stromberg carb, that was a smaller Stromberg than would be in a 383. Just like there were 2 different versions of a BBD in those years, the 383 one was much bigger. The carb shown on this engine doesn't look like the 383 version
So Bill, I don't think that's "it".
Why I said to check the PN. But, even a carb for a 318 would be oversized for a 225 slant. I understand the BBD on slants had a lower CFM rating than for a 318.
A 4 bbl carb can be even more over-sized on a slant, unless you can find one of the rare and expensive 370 cfm 4 bbl. An aftermarket TBI EFI might allow a better fit since some use regular MPFI injectors, allowing swapping in smaller ones, though haven't seen anyone try that on a slant.
