haha ill stay away from N20, i was raised with the thought that thats for people who cant build motors, no offense i just dont believe in it....who ever raised u obviously hasn't seen any PRO MOD or 10.5 shootout racing..those guys run TONS on NOS and I'm sure they can build engines..nitrous when used properly can be an inexpensive way to make power.. ..with the options u have i say there is no replacement for displacement...use the biggest engine at your disposal...and get as much comp. as you can.(i.e. mill heads/deck block).u seem to have a good enough collection of parts to make yourself a nice little hot rod.. good luck...........Al