They finally made an adaptor kit that allows you to bolt a PI Intake to your Non-PI heads. It must have just hit the market because I have been looking for a long time and have not seen it. Everything needed to make the swap comes with the kit, including the intake manifold. Check it out! Good luck, Tommy.
New - Livernois Motorsports - 1996-1998 4.6L PI Intake Adapter Kit
New - Livernois Motorsports - 1996-1998 4.6L PI Intake Adapter Kit