nope, would fit tho, wouldnt go very fast. The 550 came with the feindishly complicated 4 cam engine, output around 130 140 bhp from1500cc in the fifties.. Pretty impressive.
exactly what I was thinking. wondering if somehow metal from the engine side and metal from the car side is touching within them.sounds like there may be play in the insert? not in the material but a small gap for the engine to vibrate in? if the insert was snug, and the mount bolted on you shouldnt get a jack hammer feelign in a 4cyl 4stroke.