I know there's a few guys around my track that have had work done on their engines by some guy. Basically, the knife edging of the rod, and balancing of the internals, is usually already done at the factory on higher performance engines. They also already have extensive port work done, like the 5 port Rhody version of the RB 12. There was a recent article in one of my nitro mags that described "homegrown mods" Basically, it's like playing with fire. You could do more harm than good if you're not familiar with the techniques involved in getting more out of these engines. Alot of times, all they do is a little port work. I doubt polishing the venturi would hurt...