95 droptop

Ok, i want to pick up some gt40 heads and send them to thumper, but those are a bitch to find. So my other option is the gt40p's. Well everyone says they wont work with stock headers, is this the same with aftermarket? I have MAC longtubes. So will the p heads work with these headers? Could you send me some link about the p heads, so i can research this a little more? And a little more info on why these supposibly dont fit, would also be nice. thanks

95 droptop

and if anyone else has some link please post what you know.

ckyguy68

The Ps have a different spark plug angle for a more efficient burn. You need a "P'" specific header that aftermarket companys make.

Here is a link for Gt40p head info: http://www.stangpro.com/html/article...les/gt40p1.htm

And heres one for some P headers: http://www.mustangsplus.com/Merchant...y_Code=fordhed

They are pricey, im sure you could find a better price if you looked around.

95 droptop

I got this info from here-http://www.stangpro.com/html/articles/gt40p_files/gt40p1.htm

And they are saying that the mac's should fit. Can someone confirm this? **** buying new headers i just put these on and they were a pain in the *** i never wish to repeat. This is a very good article for anybody thinking about p heads to read btw.

Spark plug is moved down and rotated out placing the electrode closer to the center of the combustion chamber. This provides a better and more complete burn. Not only does this help performance but it also reduced emissions. Note: The GT-40P's don't use standard 5.0L plugs. You must use plugs for a 98+ Explorer/Mountaineer V8 or for a Cobra/Lightning equipped with iron GT-40 heads!! Forget about the shorty plugs (Accel p/n P526S). I've heard they're close to $10 each for this application! Plug specs are: 14mm thread, 0.708" projection, tapered seat, resistor plug. Thanks to Derek Hyde for the Accel plug specs!!. The 2000 FRPP catalog lists a Motorcraft AWSF-32C. I bought Champion Truck Plugs p/n 4013 (I used the Truck Plugs on a '97 V8 Dakota I had and was happy with them. Thought I'd try 'em again.)
[*]Standard unequal length shorty headers won't work because of this new plug location. The primary pipes make their downward turn towards the collector too soon. Central Coast Mustang offers a P-specific shorty (made by MAC) for $199 and FRPP is offering a set for about $250. I know the FRPP pieces are stainless.....not sure about the MAC....most likely their HTS coating. I thought I read once that stock tubular exhaust manifolds might work. Why bother using those though if you're upgrading the heads?

In starting my research for the header-fit table I've been told that standard FRPP unequal length shorties will work for not only the Fox application but the SN95 shorties will work for the 94-95 cars as well. These are not a perfect fit like the MAC-for-CCM shorties and will most likely require 90° boots and/or heat booties, but they are supposed to fit without any primary dimpling.
[*]Equal length shorties won't work at all. Well....sort of. Again....in researching the header-fit table it looks, via some good installed shots - don't have provider's info handy....credit will be given) that BBK equal length headers may fit. Still studying the pics for a more solid opinion on this.
[*]Some longtubes and 3/4 length headers will work. Their ability to allow the primaries a longer exit straight from the exhaust port b4 turning down towards the collector provides adequate access to the plug. I know of MAC longtubes (1 5/8"), Flowtech longtubes (1 5/8"), and Heddman longtubes (1 1/2") being used.

The Heddmans alledgedly require a small clearance dimple on the #4 primary. The MAC's are snug on the #7 primary but clear fine. CCM offers these as a longtube alternative to their P-specific shorties. I had unknown-brand 3/4 length headers (1 1/2") on my '84 (look like DynoMax) that will clear no sweat. MAC longtubes for the SN95's are a good fit. CCM finallyhas a SN95 P-fit shorty. CCM is also offering a set of Tri-Y headers for GT-40P use in classic Mustangs. This is a huge plus as I've had many questions regarding header fit for P's in classic 'Stangs.

The Flowtechs were originally thought to work and they can be used. The dimple that was said to be required in the #4 primary is more like a crater. You need to crush the primary half closed to clear everything. And you'll need wires with 90° to clear a few of the other primaries as well. Check out the Progress Page for more info on this. There's some great shots of the Flowtechs installed (and "dimpled") as well as the CCM MAC built P-specific shorties.

95 droptop

Plus, if you add it up
Heads-100
Headers-400
midpipe-200
Porting-600
Total-1300 if i spend this much i would just get afr's

AdderMk2

so 95 drop top...

I have MY GT-40's for sale... along with my Cobra 1.7rr's. If you are truely interested in sending them to thumper I could talk to him about shipping them to YOU instead of sending them back to me... therefore, I could ship them straight to him, then they would go to you. It'll save one trip worth of shipping, and some money.

95 droptop

i dont have the money right now, im just trying to research them before i buy. And ill just stick with porting my e7's if the p's wont fit, and i cant find a set like yours. but just for ****s pm me a price and i can see what i can do. I dont need the RR.

LTnone

Beautiful vert ya got there

Blck92GT

Some power or thumper heads are much improvement over just the stock castings with a backyard port job...although I didnt know Thumper did GT40's as well? Those would be some great flowing budget heads

frdmstng1986GT

yes... yes they do... and they will outflow AFR 165's when he is done with them. well, out of the box AFR 165's anyways.