Re: 350 engine swap
If it is not going to be an original car (crate motor), then it really does not matter which engine you put in...the small block dimensions are the same, regardless of model year, unless you start getting into "newer" LS type stuff...
Just re-use the pulleys, brackets, etc off of your current motor...
the only other difference that jumps to mind is a short water pump vs long water pump, but after '68, all the small block pumps were long (I think)
406, 10:1, comp xr282HR, Dart Iron Eagle 200cc, Holley Contender dual plane, Holley 750 DP
GM 8.5, 3.73 posi