guy i know built his own double turbo syst out of 2 6.5 turbos on a stock 350.He told me the best thing he bouhght was a fuel ratio meter which he has mounted in his cab. he advised it took all the guess work out of jetting it.
he was running 12.5 s in the quarter in a 1/2 ton and its a stock engine.
i would suspect that it wold help anyone who is messing with jetting especially under pressure.