GT40 vs GT40P heads, from wiki

[Rick93coupe]

"Ford offered a performance head that was a stock part on 1993 - 1995 Mustang Cobra models and pre- 1997-1/2 Ford Explorers and Mercury Mountaineers equipped with the 5.0L engine called the GT-40 head (casting id F3ZE-AA). In mid 1997, the Explorer and Mountaineer 5.0L heads were revised and re-named GT40P. The GT40P heads, unlike the GT40 heads, had a very well developed port shape/design which yielded ~200 cfm on the intake side and ~140 cfm on the exhaust side without increasing the size of the ports at all from standard E7TE castings, and without increasing the exhaust valve size. They also had smaller 59 - 61 cc combustion chambers for added compression, and the combustion chamber shape was revised to put the spark plug tip near the center of the chamber for a more even burn. These GT40P heads are extremely efficient and thus require only 28 degrees of total ignition timing to produce maximum power. Not only do GT40P heads flat out outflow regular GT40 heads, they also create more compression and a more even and more complete burn in comparison to regular GT40 heads"

http://en.wikipedia.org/wiki/Ford_Windsor_engine

Just doing some reading tonight....

[CNTLOSE]

Glad I have some "P" heads....even if having to buy the special headers is a PIA.

[heyitsmepugsley]

weerd. me two. im doing the gt40p heads with the gt40 upper and lower intakes with a tfs stage 1 cam and a paxton sn89 blower combo this winter. cant wait to see how it runs.

[mustang_gt88]

Great imfo, the headers that you would want are the ford motor sports correct? Thanks for the imfo.

[INSANEBA]

I'm building the P cmbo for my car this winter too. I'd like to low boost it just to see what it would put out, but I know what they d n/a. Idk about the headers though, I may "modify" mine lol...

[Rick93coupe]

I know guys who have used standard shorty headers, not P headers but if you don't switch to a 90 degree sparkplug boot you'll burn up your wires. Here's an example.

http://forums.corral.net/forums/94-95-tech/1328137-gt40-p-bbk-headers-sparkplug-tightening-pics.html

I got to researching some of this stuff tonight after looking at the 1st Gen lightning 351 with GT40 heads / intake.

[CNTLOSE]

Great imfo, the headers that you would want are the ford motor sports correct? Thanks for the imfo.

Yep...hard to find used and about $100 more than the MAC set up I usually get when buying new.

[mustang_gt88]

The headers I have on the car are the ford motor sport. Just need to get the heads now.

[INSANEBA]

^^^ They actually make a P specific FMS header, so make sure that you have em or you will have the same issue. I'm going for a 90 degree boot on my FMS wires, already got it covered lol... I do plan on doing a lil port work to mine, then a Dayton Performance valve job and spring set up(shameless plug) before they go ontop of my fresh bottom end though.

[Pitbull1052]

Ask Adam at S&M what a little P headed stock bottom end turbo motor put down.......

[INSANEBA]

^^^I've read

[bangingears]

Ask Adam at S&M what a little P headed stock bottom end turbo motor put down.......

what yours make? mine threw down 636rwhp at 5700 rpm...... also just something to think about, why are comp and FS guys running the regular gt40 heads if the p's are better??????? something to think about


http://www.theturboforums.com/smf/dyno-results-and-track-times-forum/636-rwhp-stock-motor/msg738195/#msg738195

[heyitsmepugsley]

has anyone on here run a blower with this setup? im curious what it will put down.

[denial]

what yours make? mine threw down 636rwhp at 5700 rpm...... also just something to think about, why are comp and FS guys running the regular gt40 heads if the p's are better??????? something to think about


http://www.theturboforums.com/smf/dyno-results-and-track-times-forum/636-rwhp-stock-motor/msg738195/#msg738195

I didn't read the forums that you posted, but the reason would probably be a lower compression. The "P" heads add more.

[90fastgt]

I just got done putting my set up.togethe its the one in my sig the gt-40 heads are milled 20 thousands its getting ready to go to Adam at S an M hopefully it puts down good numbers with the regular gt-40s I thought I heard that the normal gt-40s flowed more than the P's