Sorry, I just saw your question; either I didn't get a notification or (more likely) I missed it. I was already doing a full frame with a roll cage, so we just made the frame rail spacing the same as that for an early Mustang so the Alumaframe system would fit. I suppose the stock front subframe could be modified to accept the Alumaframe, but I would be hesitant to do that without including some additional bracing, since the spring force is now applied to the chassis at the wheels rather than at the torsion bar attachment points. Engine is an aluminum 433 c.i. 3rd gen hemi, with dry sump and Hilborn injection--about 100 pounds lighter than the 340 that I had in there since 1978. Engine mounts (and everything else) were designed and built by Hot Rod Chassis and Cycle.