msd real or knockoff

why would heat and rust be any more of a issue with the sbm than any other engine? ever see were a early ford flathead distributor bolts on, been running a mallory unilite on 36 flatty for 20 years no issue's. and about the cheap comment the widest part of a one piece billet distributor body is around 4 inches the widest part of this distributor body is now a little over 2 inches, chuck a piece of 4 in round billet in the lathe versus a 2 in piece and you would have a huge savings