Im thinking about buying some BBK shorty headers, BBK 70mm throttle body, C&L upper intake plenum. I dont not have a handheld tuner and the only power mods I have now are offroad X-pipe, Mac catback, 9mm wires, fenderwall cai. How much Horse power do you think would be added to my 96 GT with the mods Im thinking of buying? I know the mods I have now probably only added 15hp or so. Are the rest of the mods worth doing if I dont have a tuner