1966 gmc

[Rubbertiredtramp]

I am new to this forum. I seem to be registered to the 67-72 site but would rather be on the 60-66 site I dont know how to fix that. Anyway my question is about swapping engines and trannys, I am looking at a 66 gmc i really like because it is a long wide box with a big back window. The body is in pretty good condition. Unfortunately for me it is a powerglide with a mid 70s small block chevy in it. I cannot live with an automatic and dont care much for the V8 either. I have a 292 and sm420 but with the offset motor mounts on the 292 would a 250 or even a 230 be an easier swap? My main concern is motor mounts, crossmembers and getting everything located properly. Perhaps I should keep looking but the BBW is very attractive. Any thoughts on this?
.