8/21/18 update:
Progress on the bike has been slow. I bought a chain that seems to fit, but i still need to make or buy a chain tensioner. I wish i went with a solid belt drive at this point.
As a side project, one of my neighbors was throwing out this beautiful toro 622 6hp snowblower. When asked what was wrong with it he said it starts up fine, but the auger doesn't turn. Not one to turn down a chance at a free machine, i loaded into my wagon and brought it home. I figured if it beyond repair at least i would get a working 6hp engine and some nice scrap out of it.
Turns out all i needed was a measly belt. I just scored a $500+ snowblower for only 20 bucks!