I'm a rookie so have mercy on me! I have a 55 235 that I am trying to get running. The engine reportedly came out of a dump truck. It has a large heavy balancer (that weighs seven pounds) with a messed up 1/2 groove pulley that someone welded behind it. I also have a 58 235 that is scrap. It has a small harmonic balancer (that weighs three pounds)with a 3/8 groove pulley that bolts to the front of it. It also has a short shaft water pump which is great. I don't understand why there is such a difference in the balancers since they are both 235 engines (verified by casting numbers). The 3/8 pulley will not fit on the heavy balancer. I have talked to a few local mechanics and have received opposing answers. Can I put the lighter weight harmonic balancer from the 58 engine on the the 55 engine or will it cause problems? The engine will be going in my 48 pickup.