yoteehunter

You can use the intake this way, however if you plan on F/I you better use the adapter plates as the pressure will blow out and leak.

incubus1275

if you want a ton of power, do a full PI swap, cut the swirl dams out which is much better for forced induction and do a Port and Polish, thats about another 70 HP ontop of you TT kit. All of the guys who build and race 4.6's cut the swirl dams out because they are only there for better mixture for N/A and reduce emissions. It took me about 7 hours per head with a Die grinder and i think it was worth every second....

2000GT4.6

why bother sticking with the NPI heads? ported NPI heads outflow stock PI heads, but ported PI heads outflow stock NPI heads.

Good luck with the hand portjob, I would be getting ALOT of information first, as I have heard time and again that its really easy to remove too much and screw it up. What are you doing to do valve wise etc?

not that it matters, but your looking at more like 465 flywheel atm rather than 490... but who's counting

silverstang1996

are you sure ported PI's outflow ports NPI's? i heard they were about the same but being on here for awhile i'm used to you knowing what's true and what's not.

incubus1275

my friend has ported NPI heads on his 98 and i can only fit 3 fingers in the intake port. My PI heads that are ported i can fit 4. you do the math.

silverstang1996

you already did the math for me, smart allic

nanaki

if you're spending the money on forged internals, why not spend another ~$300 for a pair of PI heads? best of luck hitting that 650 mark, you have more to do than just the motor.

yoteehunter

http://forums.modulardepot.com/4-6l-...-npi-data.html

Here is the real math. The fact is that I got a set of non pi heads for free so far I have no reason to go buy pi heads as I feal I can save money and get the same results. I am out to show non pi. My first build was to show that I could make good power through stock non pi heads, and I have acomplished this. Now I am going to try to reach my power goals with non pi heads still. If it doesnt work I will switch to pi but so far I have met my goals. I will know soon enough. Personally I feel the intake is the biggest hold back and the heads are not the biggest restriction, however once the intake is swapped they can become the holding factor on power. But over all I have pretty much maxed out the stock internals as far as there strength so me initially swapping to pi heads first would have been a waste of time and money.

silverstang1996

yeah i thought that ported NPIs/PIs flew the about the same...

Frostbitten

sweet!