In that case, Id swap in a D16A6 and just do basic bolt ons... That or atleast do MPFI swap on the D15B2 (the stock engine) before you do anything else, because thats the main restriction in the system... Going from 2 to 4 injectors will help you out the most... Until you give the engine a more efficient way to receive gas, any intake and exhaust mods would pretty much be worthless...