wow! this is really interesting! alot of opinions flying around here! i can only speak from experience as i obviously had an efi manifold on my car. it made 150hp at the treads on 12psi. there was more in it! ask any experienced engine tuner and they will tell you that intake manifold design and capacity has less effect in turbo motors. there are gains but marginal. put it this way. i do not expect to gain more than 5hp on the same boost because of the manifold change.i am only changing out of necessity. the ports are too big.

about my particular manifold that is for sale. maybe people should read things a bit slower and to comprend what is being said and look at pictures in a bit more detail. the manifold is NOT modified, it has an adapter that has been build to suit the magna throttle body. you do not want the factory tb as they are junk. twin throte, holes too small. yes it comes with the injectors and fule rail. i just paid $700 for a fuel rail and injectors for my new set up... that is what it costs. sure you could buy some secondhand injectors but they would need to be serviced and that brings you close to new ones anyway. i am biulding the manifolds myself and so far in materials your looking at around $250-300 and that is with out any bends. that happen to be $40 a bend. there is no way you will build a manifold with fuel rail and injectors for less an $700! to thinking about biulding intakes manifolds out of anything other than ali.... please do yourself and your engine a favour... dont do it! there is a reason manufacturers use ali. it has a far superior heat loss efficiency rate. if you use steel or stainless you are just heating the air going into yur engine which will cause all sorts of problems.

ps. i thought those manifolds came out on atmo motors so shouldnt they work alright? just change the tb!