predator 420

Looking for some advice here. Have experience with 212's but no experience with the hemi 420's. Currently, the engine is stock except for the stage one kit to hold the place for the Mikuni 34mm and custom exhaust. Looking for top end performance. The only part I currently have is a billet...

Hey guys, I am going to use an electric start, big block, motor for my next project- a kart this time. Anyways I want to save a few bucks and get the Predator 420 motor. BUT No one makes heavy mods for it. I asked some folks at OldMiniBikes warehouse, as they have GX390 parts and 420 Parts listed...