[surfbeast]

The 99 up intake will NOT fit on your 98 heads. You have to have the 99 up heads for the 99 up intake to fit. That is part of the reason why the 99+ heads intake give more power, they have bigger and different shaped air runners. Not sure if the 99+ intakes are plastic or not but I'm pretty sure they are, I'm sure one of the guys on the board will let you know. Unfortunately the only intake out right now are very expensive, The Bullitt / FRPP intake are both about 1500.00 or more. Hopefully the aftermarket will pick up soon with a more reasonably priced intake. If you go with the roots type blower like is on the lightnings and the new 03 Cobra you don't need to change the heads and you don't need an intake. The roots type blower IS the intake. Kits can be purchased for the 98 GT from Saleen, Keeny Brown, and Roush as well as Ford. They come as kits with everything you need and are comparable in price to the superchargers. Remember the 2500.00 price for the superchargers are for just that, they dont include new MAF,injectors fuel pump etc.. Shop around and compare prices for EVERYTHING you will need to do the MOD not just the one part. Also, from what I hear the roots type blower is easier to install. Hope this helps.