Thanx for the info, gathering a avrage from what u guys said is, i wil get an increase if they are tuned right, but if i want to use them to therir fullest i need 2 flow my head do the valve's & cam, and then my back compression aka brance and free flow.

C the thing is i got the 40's from a friend who got them from a alfa Gtv 2l 16v. their in great shape and very cheap, since he doesn't have an isseu with cash. I do have an isseu with cash at the moment being a student ;P so ya i think trying won't hurt, and i have seen these 1400 nissan engine's perform on them very hectic. have a tha South -African Bakkie. Eccelent ride. anyways anymore info on what to do how to perfect plz ;P

thanx