I just got a engine, with a trany, that was in the rear of an old 52, 1/2ton pickup. My 3600, has a 216, this one seams biger,and the acorns, on the valve cover are not there.The gen.is biger also. I got some #s. #0046902T54Z on engine. 3 speed # M1026 Any ideas??? Thanks , Paul