Rob, whether or not to hang a flathead directly off the flywheel housing is an oooold debate.
Millions have done it with the 85's ... a couple probably broke and fell (?). The V8-60 is lighter. I've done it more than once and wouldn't hesitate to do it again.
(Fred, a very good friend made up a V8-60 exhaust port fixture just like the 85hp. Have never seen one for sale otherwise. EDIT: EXCEPT STUMPY"S BELOW ... thanks, Capt John.))