The sportwerks is the same as the 427 but has a better carb so teh SW has a good edge ont eh stock 427. The SW is a screaming engine. You cant run no insert on the sportwerks. It wont run right. Use the 9.0mm insert. Make sure its break it in right and lean it out just for the race. Dont worry if your temps get up near 270-280 for the race. I think you will smoke him and the revo is also heavier too so you have that advantage too.