Rap, N2O will definetly give more Gow, but I don't know how well it will cooperate with the siameese intakes, might have to use a gaseous fuel for enrichment (ie propane) as I've heard seveal stories of headaches caused by the gas making a turn that fuel didn't want to.
I've also been told that a good rule of thumb is to remove 2* of lead for each 50 Hp worth of "shot".
Of course I may be way off on what you were thinking, just guessing, was I close?
