Been working on this on and off the last few weeks. Acquired the parts I need to make a jackshaft and have been making good progress there. I was going to use a stock setup, but found that the predator engine takes up a lot of space in that part of the bike, necessitating a custom solution.
Now, this bike is a bit more hacked than I initially thought- for example, it appears the fork is made from ATC shocks with minibike crowns booger-welded directly to them. I may have to find a different fork, but we will see.
-Rob