would they match up even if the the displacement is the same

 

no

 

why????????????
explain

 

basiclly its the bolt pattern is different.

 

if u got the money to customize it, then do it dude!
but why goto D when B is soo much better -B-etter

 

The b series motors share the same displacement numbers with the d series but that's about it. Very little is interchangeable between motors. The block is completely different, and the bolt pattern for the tranny is different as someone else said.

 

Here, this should help... the thicker, beefier one is the B-series... the thinner, flimsier one is the D-series... HTH