I have two fe distributor"s - # C7AF 12131-A / 12127 with a shaft DIA of .467. it is an Autolite. The other is a Motorcraft # D8TE 12131-AA / 12127 with a shaft DIA of .531. I thought all fe's were the .467. I'm going to use one as a core. Is one any better to hang on to than the other? Thanks Jeff