i have a few of these engines and looking at the castings they appear to have blanks to drill the mounting holes for the horizontal side..
after studying the diagrams on partstree.com i see its the same internals and the oil pump which has a tube pickup. I know the carburator and governor linkage need to be reworked but thats child play, also valve lubricaton is a thought.
anyone do this conversion? i have a few to spare so if it blows up im not too worried. thinking of putting it in my bolens h14 snowblower as the oh140 is worn out.