My briggs bike is almost done. Motor on it, runs strong. But I have another motor set aside for rebuild, and during rebuild, I want to make it run. Currently has a smaller moto slide carb on it that seems to work.

What are we talking for significant increase in power? high lift cam? oversized pistons? Just looking for some opinions on what my best bets are, I can find very few parts for it. I am mostly curious about the camshaft, but havent been able to find much info on them.