jthorn9

Sorry to do this, but as I'm a little unfamiliar with the 4.6L (although I'd have a good idea), I'd like to know what the following two setups would approx make:

96-98 Mustang GT
PI Heads
Vortech V2 W/Cooler Kit
BBK Long Tube Headers
BBK H Pipe
Magnaflow Catback
Stock everything else
***I'm guestimating 330 rwhp

96-98 Mustang GT
Patriot Stage 2 Heads
Compcams Extreme Energy Stage 1 Cam
Vortech V2 W/Cooler Kit
75mm Performance Products TB and Plenum
BBK Long Tube Headers
BBK H Pipe
Magnaflow Catback
***I'm guestimating 420 rwhp

Again, I'm pretty ignorant with the 4.6L and how it responds to mods, which is why I'm asking. I have a buddy getting fed a lot of bad info from a local shop about a 97 GT he's about to buy, and I want to steer him right, but want to make sure of some power numbers first. In short, shop is trying to say a 97 with PI heads and that S/C will make 450rwhp, all I could do is laugh when I heard that. Yes I tried to talk him into a Cobra or 99-04, but he's hard headed and won't listen, so what can I say?

2000AZ5.0GT

any more information on the PSI? the First one with PI heads is probably around 400 at the wheels at about 10psi, other one, again, hard to tell without any more information, but at 10PSI would probably be around 420rwhp

jthorn9

I believe the kit is 10 PSI, not entirely sure, but I believe that's what I saw.

Also, how much better are Patriot heads over PI heads, is there a huge difference, or is it marginal?

jivepepper

Well with pi heads on a npi short block it will increase compression and output. I guess 390-400 on the first set up and 450-470 on the second one at 10 psi.

I made 516/453 with an intercooled S-trim @ 12.5 psi with stock heads, intake and Hp S292 cams. I would look into a custom grind or well known blower cams

jivepepper

I feel at lower boost levels that stock heads and a good set of blower cams are good enough.

jthorn9

So the high 300/low 400 would be possible on the first "WITHOUT" a cam swap, because a cam was mention no where on that guys pricing list for my buddy, who wants to be a 400 rwhp plus or minus a little.

2000AZ5.0GT

I think it also depends on whether or not you get a good set of patriots. They have a bad rep of having bad valve seals, I know I've had to have mine replaced, Oxford has had his replaced, I think Defcon has his replaced

2000AZ5.0GT

totally possible with full exhaust

jthorn9

OK, well that's what I wanted to know, still a bit shy of that guys 450 rwhp number he fed my buddy.

Well with that in mind about the Patriots are there any other good head brands or are PIs more than enough? I'm probably going to have to help him with this build as I know how to strip a motor apart and he doesn't, but I'll be damned if I'm doing this twice because of bad valve seals.

2000AZ5.0GT

Fox Lake heads are great

4.6L's don't have any original heads, all these companies are basically just reworking and re manufacturing stock heads.

You can do just as well getting them ported and having a valve job done locally.