OP did you ask Terry, He is still doing some work.. He's no spring chicken. The weight was the killer, last time I talked to him.. Macs are heavy.
Mike Samra, takes a while, but he is one of the best, him and Mr DeWick are best of phone buddies..
Hard to find sometimes, He's an automotive / teacher. Green sock, red sock fella... I guess he's still around... He did complete rebuilds, where Terry wouldn't.. Give you the scope before and after, BIG C20 fan..
Regards