Jim, I am guessing it is okay to put a Boyer in the old style rear mounted distributor, but not something like a Trispark?
Stephen Hill
yes, so nothing simple like bolting on the newer cover & adding parts?If you are thinking of the ignition that is mounted to the end of the cam as on the newer engines then there is no place to mount an ignition on the end of the cam on the old engines.
.
are you talking only at the mag sprocket area? or including the chain to the mid double sprocket?Yep, definitely newer cases and likely some kind of custom drive inside- since I doubt that the original magneto drive would last more than a few miles driving a blower.