good gt40p head reading, couple questions.

fivespeedsteed

Dirt-Old 20+Year Member
Oct 17, 2003
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Richmond, VA
was piddling around at the junkyard the other day, saw that a set of heads would probably set me back 80 dollars or so.

where can i find some good reading on all the stuff thats required for the swap, as well as what cars i should be looking for as candidates to pull the heads off of , ie, what years, explorer vs mountaineer, what to look for when getting them to make sure they will be useable.

from what i gather, im looking for 96 5.0 explorer heads so i can keep using my smog/egr stuff

then i would for sure be running a cam of some sort, like a tfs1, e303, ect, so that means valve springs

then i got a quote from a local machine shop for 285 to do a 3 angle valve job, hot tank them, mill them flat, pressure check, and i think that includes valve seals.

then ford racing gt40p headers for 230 ish IIRC off latemodel

then an intake manifold of some sort, probably the one off the explorer, maybe get it ported?

gasket kit for the whole motor since every gasket leaks

the explorer TB

24 lb injectors? 190 lph pump?

then once i have all that stuff ready to go then id probably pull the motor since all the gaskets leak. id feel obligated to pull the short block apart and have it blue printed, bored .30 over, check the crank and grind .10 under if needed, then rod and main bearings.

the goal is to have a good solid 250 hp minimum wheel hp car, with all my smog/egr stuff and AC.

do i sound on the right track?

edit:

http://www.summitracing.com/parts/FEM-MHP173-311/ looks like a decent option? .030 over pistons, .010 under rod and main bearings, all sorts of gaskets, ect.
 
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the 95 to early-ish 97 exploders and mercury mountaineers had the regular gt40 heads..the later models to 2001 had the gt40p's

the regular gt40's dont require any certain headers..the gt40p's do..headers known to work are mac longtube and P shorty, ford racing shorty, bbk longtube and shorty..some of those require the use of plug wires with 90* boots

none of the explorer/mountaineer gt40 or gt40p heads have the AIR system holes drilled..you can bolt your smog stuff on the back fo the heads, but it wont be operational..as far as i know the only gt40's that had the AIR holes drilled would come from the 93-95 cobras and first gen lightning pickups

they all have the EGR ports in them though

the exploder tb is 65mm an upgrade from stock, but requires modification of the butterfly thing on the bottom to use with a fox mustang
 
so any later ish 97 to 01 explorer/moutaineer is what im looking for? where or what does the tag on the heads say to tell me they are p heads?

is it completley stupid to use my stock short block with no machiene work and put heads on it? im almost thinking it might be worth it to pull the whole motor out of the explorer that way i can build it while im driving the car then swap it all at once
 
yeah 97-later if you want the P heads
97-earlier if you wnat regular GT40's..
97 had a mix of both regular an P's
quickest way to tell if you look thru the wheel opening, by the rear spark plug on the drivers side it'll either say GT or GTP
GT is the regular GT40, GTP is the GT40P
 
I think the p's have 4 dashes on the front of the head and the 40's have 3 dashes.. Might not be a bad idea to just grab the whole motor and just freshen it up. Then swap motors and sell you current motor whole. That's what I am doing but with a 351 instead. But I should be able to sell my complete motor with p heads and low miles for 700$ or so.
 
Id almost feel bad pulling my 108k mile motor apart and redoing it it runs great and doesent burn any oil. But id need stuff off my fox motor to put on the exploder motor anyways right? Oil pump/pan, stuff like that. That would be worth doing if I cound build the entire motor then swap it straight up

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So what would be more dumb to get the heads done up at a machiene shop then put them on the stock shortblock and save myself from pullin apart the perfectly good shortblock, or to pull apart the pefrectly fine short block and have it all blueprinted?

There would be no need to go more than a 306 with the p heads right? Can I make 260 whp with unported p heads?

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Neither choice is really "dumb" IMO, it's whatever you feel like doing. If your current engine has good compression, good ring seal, and no other known issues, there's nothing wrong with dropping on a fresh set of heads. I don't know about how much power you could expect with P heads, but I know they're a helluva improvement over stock E7s...I think with no other changes (edit: except springs like you mentioned), they'd be worth probably 20-25, if not a little more. The P heads were really made for more torque production on stock 5.0 engines anyway, so you'll have a strong running engine regardless. If you slide in a TFS1 cam with the exploder top end, you'd have a solid running longblock. The 24lb'ers with a 190 pump would definitely be a good idea-AFPR would probably be good too if you haven't already done that. I'm not sure of the TB size from the exploder though-aren't they like 65mm from the factory?

If you're just looking for a fun driveable street engine, that combo would be fun for a while...then throw on a blower :D
 
Neither choice is really "dumb" IMO, it's whatever you feel like doing. If your current engine has good compression, good ring seal, and no other known issues, there's nothing wrong with dropping on a fresh set of heads. I don't know about how much power you could expect with P heads, but I know they're a helluva improvement over stock E7s...I think with no other changes (edit: except springs like you mentioned), they'd be worth probably 20-25, if not a little more. The P heads were really made for more torque production on stock 5.0 engines anyway, so you'll have a strong running engine regardless. If you slide in a TFS1 cam with the exploder top end, you'd have a solid running longblock. The 24lb'ers with a 190 pump would definitely be a good idea-AFPR would probably be good too if you haven't already done that. I'm not sure of the TB size from the exploder though-aren't they like 65mm from the factory?

If you're just looking for a fun driveable street engine, that combo would be fun for a while...then throw on a blower :D

i agree with this
mine made 270/300 at the tires, maxing out the stock fuel pump and injectors, and also had some valve spring issues(wrong keepers came in the kit and springs were installed too high, only putting like 90lbs on the seat)

i just went for the 255lph pump, do it once and forget about it..if you put a blower on down the road, you'll need it anyway

never re-dyno'd after fixing the springs and stuff, but i would guess it probably picked up another 10-15hp by removing the power steering, adding UD pullies,fuel pump, 125lbs on the seat at the valve springs, etc..

250at the tires should be easy
 
can a machiene shop check for the mount surface of the heads being flat without pulling the rotating assembly out? thats mainly what im worried about. if the block is warped i dont wanna put a set of flat heads on it and have head gasket issues. but then if that theory holds true id have head gasket issues right now unless the heads warped with the head mount surface.

ill probably just stockpile parts and do it all at once, i dont really want to have another motor since i think it would be more of a PITA to sell my motor once i get the new one in.

so the list is

gt40p heads
p headers
machiene shop the heads
gasket set
tfs1 cam
some form of ported explorer or cobra intake manifold
24lb injectors
190lph pump
65 or 70 mm tb

what else am i missing?
 
The 255 pump as mentioned above :). The 190 would be ok if you never plan on upgrading power level, but like was mentioned, if you do decide to up the ante later, you'll need a bigger pump. And the 255 costs the same...no losses, only gains


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just mill the heads..while decks do get warped, its not nearly as often as the heads being warped..you should be fine there
missing from that list, in my opinion:

valve springs
255 fuel pump
hardened pushrods
roller rockers
75-80mm mass air
longtubes
 
So what would be more dumb to get the heads done up at a machiene shop then put them on the stock shortblock and save myself from pullin apart the perfectly good shortblock, or to pull apart the pefrectly fine short block and have it all blueprinted?

There would be no need to go more than a 306 with the p heads right? Can I make 260 whp with unported p heads?

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I am at 260 right now with unported p heads. But there are people making more
 
The rotating kit you linked from summit had flats with no valve reliefs, didnt all foxes have reliefs? Would there be P-t-V clearance issues? I am actually about to do the same swap with Ported P heads, ported Explorer manifold, 70mm TB on my 87 speed density