I've got what are supposed to be ported pistons from vito's. K&N with no lid, the 34mm round slide mikuni's, aftermarket intake with built in crossover, v3 reeds, cool head with 19cc domes, fmf sst's with matching silencers, and + 4 timing. Still have stock gearing. As far as a leak down test, not sure what that is? Just spraying down everything in front of the air box with carb and choke cleaner to test for leaks??? Also having a problem with the head pipes getting to seal 100% at the jugs. The o rings just don't seem to be fat enough! Thanks guys!