another questions,

If it is a 4.6 with stock NPI heads/cams/intake. would you recommend getting an aftermarket intake/intake manifold or would it not make much of a difference?

 

I dont know if it will make that much of a difference. The biggest thing is find some pi heads and cams and do the swap. Other than that, dont really bother with the plastic pi manifold. Without the pi head/cam swap, you might be in the low 300's rwhp. With the pi swap you will be close to 400rwhp. So up to you about where you wanna be.

 

Is the FMU needed if you get a custom tune? I was just reading Vortech's site and it just seems to increase fuel delivery in accordance with boost.

Thanks.

I think that's what you mentioned before, I just want to make sure

 

Simple answer, no