throttle bodies/ intake manifolds

[perna00]

i've found alot of different opinions on throttle bodys and manifolds. if i am to swap out a diamante or gts intake manifold, do i need to swap out the upper, lower, or both manifolds? i've also heard of a guy that custom builds stock manifolds into short manifolds; any info on that? another thing, what is the best way to upgrade throttle bodies? i've heard of getting the stock one bored out (proflow, i think) that makes them. any info? also, is the stock throttle body off a gts or diamante larger than mine (01 gt spyder)?

[eclipsed4utoo]

i think that you only change the upper intake manifold when swapping with the diamante or the gts. yeah ive seen the website of the guy that custom makes the manifolds. they looked good to me. as for the throttle bodies, i think going with the proflow throttle bodies is better. i think the gts throttle body is bigger

[perna00]

thanks. anyone know what the expected gains could be in terms of swaping parts. i've heard the proflow throttle body adds like 4 hp. any idea on the intake?

[eclipsed4utoo]

i think the intake is like 5hp

[perna00]

now the question is if the lower plenums are the same for both intakes. i'm trying to find out if i just need the upper or if i need both. anyone know for sure?