Ok I have a slight problem. The engine I'm building is ending up with GTP-40 heads instead of GT-40 heads. The reason is that we (me or the machiene shop) couldn't find a decent set of GT-40 iron heads that didn't cost an insane ammount of $$$$$$. So now I have a problem. I'm guessing that with stock Mustang/MK VII headers my plug wires are going to hit the headers. So here's my question: is there any set of plug wires for the 5.0 that will clear the stock HO headers with GTP-40 heads or do I need to get some headers? If so what headers will fit so I don't have to hack the out of my motor mounts to get them in? Thanks guys:D
BBK headers, and spark plugs for a chevy truck are known to work. Cougarman did that on his car.
Personally, id do the BBK shorties, and buy some cut to fits, to ensure a good fit.
I read some where I think one of these mustang web-sites that the stock stang headers will fit. Remember the 95 Cobra-R came w/GTP heads so if you can a least find a header off a 94-95 stang you will be alright. But they are very similar to fox headers.
But my advice is since your doing your motor nice put a nice pretty set of headers on just before ordering check if there “p” compatible though most are now.
1995 Mustang Cobra R's had the standard GT-40 cylinder heads with the 1.84" intake, and 1.54" exhaust valves.
The GT-40P heads have a 1.48" exhaust valve.
The only domestic production vehicle to get the GT-40P head was the 1996-2001 Explorer/Mountaineer.
BTW, they made their first appearance on the Ford Racing catalog in 2000 (M-6049-P303)
Brent
I have a set of 1 5/8 unequal length mustang headers for mine,and the stock wires clear.Also i have the metal sleeves that the Mountaineer used to help with the heat.
I have gt40p heads on my convertible and I would buy the headers designed to fit. I didn't put this together got a steal on the car last year and went to give it a tune up what a pain in the yin yang!! If I wouldn't have been short of funds at the time I would have changed them out then. Instead I'm building another engine with just e7's. I'm not real impressed with them anyway but, could be that the engine is just on its last leg lol. I would buy the header designed for them though. Will make life alot easier in the long run. Just my .02
I got MAC headers on Ebay for my setup. I haven't put it together yet but these headers are supposed to be for the "p" heads
Well I'm just going to bite the bullit and pay $250 for the FMS stainless steel P headers at Summit. Actually with the headers it still comes out cheaper than getting decent rebuidable GT-40 heads:screwy: . On the bright side the heads I have are brand new and have never been rebuilt or used before.
I have got a 98 Explorer engine with the P heads. I hooked up a pair of BBK Fox headers and the plug wires to use need to be 90 degree spark plug boots.
I have two more questions for you guys.
Has anyone installed the FMS GT-40P swap headers (M-9430-P50) and had a motor mount interference problem? I know people have had to cut their motor mount brackets to get the stock HO headers in but mine went in with no interference problem. I have about 1/4" clearance between the *U* bracket and the top bracket on both sides. I'm guessing that since these are 1&5/8" primaries that they will be a little bigger than the 1&1/2" primaries of the stock HO headers. I'm going to try not to cut the mounts so I might just, uh, dimple them if I have to so they fit:hick: .
For those who have removed the thermactor system conneted to the heads (the GT-40P heads don't have the holes in the back of the heads and I don't have to pass emissions) how did you run the line to the cats? I'm leaving the air pump and cats on for now till I get a catless H-pipe and to work right they need the pump. Or do I just cap off the line to the back of the head? Any pics would help:D
http://www.foxtbirdcougarforums.com/showthread.php?t=10125&highlight=header
And as for the smog pump disconnect every thing and block it off at the cats. Real easy.
From my research the 95 cobras came w/GT40 heads but the same year 95 cobra-R came w/the GT40P this was to be the next generation 5.0 till emissions standards kill the push rod motor and they went to the 4.6 but the lucky trucks like explorers ect. got the latest in tech from the mustang engineers there’s a lot more to the story but another day.
so my only proof is what I read but if you ever see a very rare cobra-R look at the heads.
Hmm I'm not cutting my mount up. Looks like ball pean hammer time:hick:. Funny though that the passenger one fit fine but the driver's side doesn't. The header was only about 1/4 inch too low correct? If so I'm not too worried about denting the header.
One more thing. Do you have a pic of the car with the FMS shorties on?
Well I don't have one real close but I do know of one that is about 150 miles away. A good friend of mine has a '95 Cobra "R", and a '93 Cobra "R" as well. Both of them raced in SCCA so they have a race history.
I will give him a call.
Well, I talked to my friend with the Cobra "R" and he confirmed that the cylinder heads on the '93 & '95 Cobra "R" Mustangs are standard production GT-40 cast iron heads. The same heads as the regular production Mustang Cobra with 1.84 & 1.54 intake & exhaust valves.
Engines with "P" heads did not start production till 11/6/96. As all 96 Explorers and very early 97 Explorer/Mountaineer had standard GT40 heads with 1.54 exh valves and 3 hash marks with 65-66cc chambers. The same head as the Cobra, but the Cobra heads had the thermactor passage drilled and were milled 0.030 for 61cc chambers. The "R" used the Lightning head which had 1/2 head bolts and not milled for 65.5cc chambers. The P heads were never planned for a Mustang, as they did not start on them until after the last run of push rod Mustangs were being built. The P was made to keep the Explorers clean into at least the 2000 model year, as the standard headed ones were only clean enough to meet 98 standards.
So what's the better head technically, the GT-40 or the P?
The GT-40 "P" head is a production cast iron Explorer/Mountaineer head only. It was designed specifically for this application only and was utilized "ONLY" on this application. The head design is the FORD answer to the Vortec head. The design is similar to the GT-40 as it fits a small block and has a 1.84 intake valve but that is it. The "P" head is the highest flowing production head made just for the 302. (with exception of the BOSS/Cleveland head). 400hp is easily attained with good exhaust and intake systems.
The GT-40 head was utilized on early Explorers and Mountaineers but also used in the GT-40 packages from Ford, Cobra R cars, and Ford Lightnings. These heads flow well compared to the E7TE on the HO motor but, would fall short when compared to the "P" head.
HEADERS, I have a set of the headers from FRPP and they will not fit your Thunderbird without complete mutilation of the drivers side motor mount. I eliminated the hydro/rubber damper and fabricted a solid motor mount. You can change your K member to the mustang style and utilize their headers and motor mounts. :birdsmily:
Or I could just *dimple* the lower tube. I plan on doing that. I'm not too worried about the flow being down as I'm not building an all out race engine or anything.
How's this coming along? Got the motor in yet?
As by *dimple*, you must mean smash it flat. That header will not fit what so ever after dimpleing it. I tried and had to modify the motor mount. I am not leading you astray. The header will NOT fit a T-Bird without modifying the motor mount and removing the rubber mount. GOOD LUCK.... I hope that it fits better for you.
I can be wrong I don’t know this for a fact other than I read I in one of my 5.0 books which I recall it stating only the 95 cobra-R came w/the 'P's but it wouldn’t be the first time I read bad info from a book.