I didn't think it was going to be easy, just hoping there was a knowledge bank to draw on. And the "quiet" restriction doesn't help with the diesel option.
I personally like the early small block option. Both the Chevy and Ford's will fit pretty well (if you count clearances in fractions of inches). After all, the ford COE's are just as tight and they has flathead V-8 since the 30's.
Everything since the real small blocks have a shallower V and bigger heads so the engine is actually much wider.
I have a Chevy LS block, heads, and a 4l80E transmission all made out of plastic to work out the fitting. Bolted on Corvette exhaust manifolds.
Had to move it so far back before it would fit between the frame rails and cab frame, that the front of the engine is behind the transmission cross member and the back of the block is sticking out behind the back of the cab.
With a 283 V-8 and 4 speed with PTO, the original bellhousing mounts are used and the engine is almost a perfect fit for the floor hatches. The only problem is the rear mounted distributor. Had to cut the floor away into the seat riser. Problem solved with a Ford 302 with front mounted dist.
So far that isn't "modern" enough, but I'm working on it.
