The LA engine is easy to swap in. I dropped a 318 in my 1941 using the steel motor mounts from a 1977 d100. The bolts go right down through the original holes in the stock k member. I used a 904 and crossmember from the 1977. The cross member went right in after drilling four holes into my frame. 1972 to 1980 8.25 rear bolted in perfectly on stock leaf springs using matching 70s shock mounts and proper u bolts.

The engine mounting maybe to far foward and cause radiator fitment issues but I may mount radiator in bed area. I used a large starter because a mini would not fit due to shape. I shaved a little off the plastic on big starter and it is tight but it clears steering box.

This is the low cost way to keep it mopar. The only gm part is my 1wire alternator....