M.O.R.E. JM200 Bomb Proof Motor Mounts / Polyurethane Jeep CJ Converting to Chevy V-8 Engine JM200 Jeep CJs, all, converting to Chevy V8 engines (small or big block). These mounts are prepunched for existing holes in the frame, however some applications require welding. They will offset the engine slightly to the drivers side for front driveshaft clearance. You must use a transfer case with a passenger side front drive shaft (Dana 18, Dana 20, Dana 300. Quadratrac, etc.) Bare steel, no zinc plating available. 9x9x9