Ok, I am getting a set of NPI heads with only 40,000 miles on them, set of PI cams, and PI valve springs all for free. I have a 1997 GT with 154,XXX miles on her but still runs like a champ. My heads have some bad valve guide seals, so she is starting to smoke. If I get these newer heads P&P'd, and with the PI cams, what kinda power will that intel for me? My car has 373's, Flowbastard Super 40's, and a MAC o/r H-Pipe. Also, is there a difference in PI springs and NPI valve springs?? I getting them cuz the guy just wants this stuff out of his garage. I just want to say this forum is AWESOME!! :headbang: I dont post much, but i have found out so much info on my car and projects i have done on my car, this forum has been the one to help me through that stuff. A big thanks and a big thumbs up to this forum :thumbsup: Keep this place alive and going!
PI cams in NPI heads......
- Thread starter 97orngegt
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topping973
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Springs will not make a difference.... NPI P&P heads are disputably hard to do correctly .... but the springs are won't make a difference....
modulars peter out cause we lack air flow. therefore any p&p'ing is worth the trouble even if you do it yourself. research it DEEPLY before doing the porting yourself. hence SVO heads are npi but the exhaust end is opened up. hence why they get more HP gain. and the valves are off centerline 2mm to prevent shrouding.
simplyme0484
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First, the springs will fit perfectly. The only difference is that the PI springs ar a bit more stiff since the cams have .550 lift compared to the npi .500.
Second, w/ pp npi heads you'll get around 20-30rwhp more but it depends a lot on other things like LT's, PI intake, tunning and the cam size. My advise to you would be get the npi heads pp, get LT's, tunning and a PI intake. There U ar talking about 50+ rwhp and the difference is AWESOME!!!!!!!! Trust me.... Anything else just let me know
Second, w/ pp npi heads you'll get around 20-30rwhp more but it depends a lot on other things like LT's, PI intake, tunning and the cam size. My advise to you would be get the npi heads pp, get LT's, tunning and a PI intake. There U ar talking about 50+ rwhp and the difference is AWESOME!!!!!!!! Trust me.... Anything else just let me know
duff daddy
Legend
everything ive read is a that a ported and polished npi head will out flow a stock pi head ..correct
Thats what I have researched. P&P'd NPI heads will flow the same or alittle better than a stock PI head. How much will a P&P cost me (estimate)? I was just going to buy a PI head kit that i found, but Im getting these heads and cams for free. Or I might just install these heads and cams and have my old heads rebuilt and P&P'd, and save them for when i rebuild my motor next winter. Can the NPI heads handle the lift of the PI cams without any trouble?? Thanks for your guys help. :headbang:
head work is expensive especially when you consider that you could pick up a set of stock PI's for a couple hundred bucks and have them ported and have some serious gains. Expect to pay $800+ for any real head work and $800 won't buy much.
Ok then. That made my mind up. I am just going to install these newer NPI heads with the pi cams in them and just run the piss out of the car at the track, and rebuild my motor and pick up some Ported PI heads for my rebuilt motor. Do the PI cams in stock NPI heads even make a difference?? Or should I just pick up some NPI stage 1 cams from Comp or CMS?? My ultimate goal is to get to low 13's high 12's... I have MAC o/r h-pipe,FLowbastard 40's, 24lbs injectors, king cobra clutch, draglite rims with BFgoodrich 10.5 drag radials. Also dyno tuned for 92 octane street tune. It dynoed at 242 rwhp/267ftlbs torque. It runs pretty mean for a 154,xxx mile car. :la:
