Hello, I am in the process of bolting on a nice pair of GT40P heads on my 1987 Mustang GT with the matching upper/lower GT40 intake. My question is: Would the GT40P valve springs handle the stock .444 lift H.O. roller cam? Or would I have to change the springs? The heads and intake are from a 1999 Explorer. Any advice is greatly appreciated. Thanks
Gt40p Heads With Stock H.o. Roller Cam
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Not a great idea to run them. I would go ahead and change them. They are 15 year old springs, designed for a lesser cam with lesser rpm's. Upgrading would be a good investment.
Joe
Joe
mikestang63
SN Certified Technician
mikestang63
SN Certified Technician
mikestang63
SN Certified Technician
fords2live
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- Apr 12, 2013
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Crane cams valve springs. 44308-1. Awesome set of springs, and they're. Designed for factory heads. Had a .544 lift cam and would twist 7k no problem. Summit Racing $170
mikestang63
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marc.riffle.5
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Holy Crap....Fram Filters were $4 in 1972!?! That was a fortune back then! And I'd gladly pay $200 for a main bearing job today. That wouldn't even cover a fraction of the labour to now a days.
Agreed....best bang for the buck springs right there.
Pretty hard to beat springs, retainers and locks for $95
http://www.alexsparts.com/valve-spr...-and-1-6-or-1-7-ratio-rockers-up-to-480-lift/
Thanks for all the helpful replies. Just picked up the GT40P drop-in valve springs that are good up to a .544 lift through Alexparts. com One last question: What can I expect after the GT40 upper/lower intake and the P heads are installed? I also picked up a 1 inch spacer that sits between the upper and lower intake. I am running a built AOD with a manual valve body and TCI 2500-3000 stall. Aluminum driveshaft with the 8.8 rear and 3.73s The 302 was rebuilt about 3 years ago with 21,000 on the motor, currently running the stock EFI upper and lower intake, 70mm TB, BBK cold air intake through the fender, 19lb injectors, stock H.O. roller cam w/.444 lift. BBK shortys, stock E7TE heads that have been reworked. Flowmaster exhaust, no cats!
The heads and intake alone are probably good for about 30-35hp over what you're making now...most of which will show up in the mid and top end regions. Don't forget to send the heads in for a good valve job and have the guides check for wear. Some of these old GT40 heads have a lot of miles on them.
I just did this. GT40p heads, explorer intake with stock cam. I also added 1.7 roller rockers. My intake was dirt cheap just 60 bucks, heads were 100, but my machining costed 500 plus 100 for springs (valve job, milled, springs, fixed bolt hole, and cleaning for them and intake), so for 700 maybe aluminums would have been better from a financial standpoint, but who knows, I actually dont regret it. They are solid and added a noticeable kick in the butt, but not anything insane. Car occasionally busts loose in 2nd from a roll, thats with stock 3.08 rear gears too, and would never have done that before. I like the mental part of having Ford parts and irons that wont bust as easily as aluminum. Car did a 13.8@102 after the swap, no before time but I would have to think mid 14's at best being basically stock except for exhaust. I would say just do the springs and not worry about it. Even if the stockers are OK, bit better springs will probably help with upper rpm power.
I am using BBK ceramic coated shortie headers on my foxbody, which are still bolted to the stock E7 heads. I have GT40P heads that are going on the motor soon, and my headers will work without any issues. BBK and MAC, also Ford Racing headers will bolt up with no clearance issues. Some of the header applications require a 90 degree angle sparkplug boot on some of the spark plug locations. You will just have to check to see which ones they are. They also sell the specific "P" headers specifically made for the P heads, but are a little pricey around $300 on up. Hope this helps!
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