I have been researching a 224 ci. Mercruiser four. Same bore X stroke as a 429 BBF. Supposidly it uses a GM bell housing bolt pattern after removing 0.085 thou'. from the rear of the alum'. block. I can pick up an alum'. 429-460 head locally from a dragracer who lunched his BBF w/ valves through the head (rod broke). One of the heads is repairable. I would like to put it in an '83-'84 short bed Ranger. The 3.7L has no smog of anykind except a PCV system and appears to fall into the "crate engine" catagory as far as smog dogma goes. There is a 4BBL manifold available for it and Ford BB header would fit as well as pistons,rocker assemblys,etc. 245-250 ci appears to be the limit due to internal block clearences. Any thuoghtful input appreciated awa smart-a''''' stuph. Thank you.:jester: