WTB GT40 Heads

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plowboy34
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WTB GT40 Heads

Post by plowboy34 »

I was just wondering if anyone out there had a set of GT40 heads they were looking to sell. I don't want the "P" heads now just the GT40 heads. If you do let me know what's you got please.

Malcolm, I know this probably should have been in the For Sale forum just figured it would get more exposure here. If you want to move it there will be no hard feelings, I almost put it over there anyway's..... :?:
Dirt is for Farming....Asphalt is for Racing

85 Ranger 5.0, GTP Engine, Carbed, AOD, 7.5 3:45 rear gear(for now)
77 Mustang II 302, C4, 8" rearend 3:00 gears, 4 point roll bar
73 Mustang Convertible, Bone Stock, 48,000 original miles
91 F-250 5.8W(really needs a 460) 4X4
2000 Mustang 3.8 V6, Bone Stock
2011 Ford Fusion (Momma's hot rod)

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Soul
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Re: WTB GT40 Heads

Post by Soul »

I have a complete 2000 explorer motor if interested, not sure what heads it has (think it is the p) but I also have some mustang headers that fit if I'm not mistaken. Plus its almost local to you lol.

Let me check with Dad tonight.

PS HI, I haven't been hiding just been rough year for me.
87 Ranger: Coast High Performance 331 kit 28oz balance, Comp XE264HR14 cam, 64cc 185 AFR heads, 1.7 roller rockers, Full manual reverse VB c4

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cgrey8
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Re: WTB GT40 Heads

Post by cgrey8 »

Yeah, that 2000 Explorer engine will be GT40p heads if it is stock.

The only production engines with GT40 heads were the 93-95 5.0L Cobras and the 96 & very early 97 Explorer 5.0Ls. The vast majority of the 97s (aka 97¼) were topped with the newer GT40p heads to meet more stringent emission standards. The Cobra GT40 heads had additional machine work done to them by SVT that I don't believe the Explorer's got to true-up the combustion chamber volumes to their rated volumes from cylinder to cylinder. This included both decking and chamber shaving. When I cc'd my GT40p heads, I found they were not at spec either. Ford spec is for GT40p heads to have a 58cc chamber. I found my chambers closer to 62-64cc. Even after .010" decking, all were still closer to 61cc. I don't recall what the spec is for GT40 chambers but I'm sure a Google search can make short work of that.

Bottom line, good luck finding a good set of GT40 heads for a reasonable price. Their scarcity raises their value, but their mediocrity compared to aftermarket heads makes them really not worth much a whole lot. The good news about GT40 heads is they do have the larger exhaust valves so they can be ported to flow more than the GT40p heads. But both in stock form, the GT40p heads with 1.46" exahust valves actually outflow their older GT40 brothers with 1.54" exhaust valves.

So why the GT40 heads? Is it just to avoid the sparkplug angle issue? For a Ranger conversion, that's an understandable concern since their are cost, fitment, or performance issues with any of the GT40p header/manifold options. But for any other project with a bigger engine bay, the non-Explorer specific GT40p headers out there make the GT40p heads a little better (and cheaper) option than the GT40s.
...Always Somethin'

89 Ranger Supercab, 331, ported GT40p heads w/1.6RRs, Crane Powermax 2020 cam, ported Explorer lower, FMS Explorer (GT40p) headers, aftermarket T5 'Z-Spec', 8.8" rear w/3.27s, Powertrax Locker, A9L w/Moates QuarterHorse, Innovate LC-1, James Duff traction bars, iDelta DC Fan controller

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plowboy34
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Re: WTB GT40 Heads

Post by plowboy34 »

No Ranger project, got a 351 in a F250 that just doesn't have enough umph for me. So the say these heads a certain cam and headers and a little intake port work will do wonders actually reachin 70+ more ponies and torque I was gonna port the E7's but learned a good set of these will be much better. I have just got to get this thing to pull and I didn't want aluminum heads cause it's gonna be a horse, Don't wanna do a 460 swap and have been garunteed this will work and that I will be able to pull like a freight train

We'll See
Dirt is for Farming....Asphalt is for Racing

85 Ranger 5.0, GTP Engine, Carbed, AOD, 7.5 3:45 rear gear(for now)
77 Mustang II 302, C4, 8" rearend 3:00 gears, 4 point roll bar
73 Mustang Convertible, Bone Stock, 48,000 original miles
91 F-250 5.8W(really needs a 460) 4X4
2000 Mustang 3.8 V6, Bone Stock
2011 Ford Fusion (Momma's hot rod)

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cgrey8
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Re: WTB GT40 Heads

Post by cgrey8 »

For torque, you won't want to go with the beloved E303. That's NOT good for low end torque as you likely already know. If this is a budget build, the best bang for your buck for torque are the replica 93-95 Cobra cams. If you can afford some cheap 1.7RRs, that'll benefit you even more. Believe it or not, the Cobra cam is more torque oriented than the stock GT cam. It's a better cam all the way around.

If you don't mind buying an aftermarket cam, the Crane Powermax 2020 (pn444211) or the Crane Powermax 2030 (pn 444221) are great truck-cams. The comp close equivalents are the Comp XE258HR12 and the XE264HR12. Check eBay and/or Craigs list for people selling used ones. There was a guy selling a 2030 a while back on eBay for $125, but I didn't need it. It never did sell and he never relisted it. I told him I'd give him $85 for it just because they don't come along that often but I couldn't justify $125 since I already have a 2020 for my setup. But he didn't take me up on that offer.

The 2020 and XE258HR are low RPM, high torque cams. They'll begin to fall on their face around 5500. But they have a solid idle, good off-idle torque production, and peak around 4000 RPMs (lower than the stock GT cam). The 2030 and XE264HR are actually not bad street performance cams. They peak closer to 4500 but hold to ~5800RPMs. All 4 would require new springs, retainers, and 1.6RRs to support their .500"+ lifts. You would NOT want to run stock rockers with these.

And of course, I'm making the assumption that this is, or could be, a roller block (85 or newer casting). As long as the casting is 85 or newer, you should have the provisions to drill-n-tap it to be a roller block even if it currently is a non-roller setup. Of course, you'd need to go on eBay and pickup a set of roller lifters, dog bones, and spider. I can't remember who it was here that did that, but they posted pics of it and sure enough, it handled standard stock roller lifters just fine.

As for head porting, the E7s can be ported about however you want and will gain over stock. That's not to say there aren't techniques that make them flow better. It's more a telling of how crappy they are in stock form. Expert porters have techniques that will give E7s very impressive flow numbers that compare to low end aftermarket heads. But even when you don't follow any particular technique and hog them out, just doing the porting will give improvements on them. The GT40 and GT40p both can be ported to be better than they are. Bowl work is where most of your gains will come from. There's a number of sharp edges that can be knocked down to get significant improvements. The ports though are pretty well shaped as they are. You can open them, but on the exhaust port, there's one side you DO NOT want to touch. There's already a bad flow characteristic at light flow rates on the port & gasket-matching the port will actually make it worse and REDUCE your flow over stock. I believe the GT40 has a similar issue but I've never found a site that covers porting them like I did for the E7 and GT40p. However if you are looking at putting the heads on in stock form, then the GT40p heads give both higher flow AND more torque than the GT40 heads.

Porting the intake is also a great idea if you have aluminum porting bits. Two weekends ago, I got 5 of the 8 ports on my Explorer/GT40 intake ported. It's amazing how much metal Ford puts in the way of flow. And it appears to be put there on purpose. Best I can figure is it has something to do with emissions...likely trying to maintain flow velocity or perhaps routing the air in a different way to get a better atomization of the fuel. Regardless, the humps they put in the flow path right at the ports are just begging to be knocked down to make room for unobstructed flow. While this is on an Explorer/GT40 lower intake, I believe the stock GT intakes also suffer from the same. It would stand to reason that the truck intakes would be the same.
...Always Somethin'

89 Ranger Supercab, 331, ported GT40p heads w/1.6RRs, Crane Powermax 2020 cam, ported Explorer lower, FMS Explorer (GT40p) headers, aftermarket T5 'Z-Spec', 8.8" rear w/3.27s, Powertrax Locker, A9L w/Moates QuarterHorse, Innovate LC-1, James Duff traction bars, iDelta DC Fan controller

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plowboy34
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Re: WTB GT40 Heads

Post by plowboy34 »

No I'm not running the E303, this thing is speed density and that cam would never help it. I have hooked up with a guy who knows these speed density rigs and he has me set up. He claims it will walk the dog like it has a 460 in it. I have always ran 460's in my farm trucks, only reason I bought this truck is it only had 86,000 miles on it and it was a good deal and a very nice truck. I knew the 351 wouldn't have what the 460's do but this thing is a pooch.

I have ported many E7's and have no problem with them but he said the gt40's would be better. Already have the 1.7 RR, thanks for the info on cams but already have that too.
Dirt is for Farming....Asphalt is for Racing

85 Ranger 5.0, GTP Engine, Carbed, AOD, 7.5 3:45 rear gear(for now)
77 Mustang II 302, C4, 8" rearend 3:00 gears, 4 point roll bar
73 Mustang Convertible, Bone Stock, 48,000 original miles
91 F-250 5.8W(really needs a 460) 4X4
2000 Mustang 3.8 V6, Bone Stock
2011 Ford Fusion (Momma's hot rod)

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cgrey8
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Re: WTB GT40 Heads

Post by cgrey8 »

I forgot all about the trucks being SD. The F-series trucks that are roller use the same cam Ford put in the Explorers. And yes that cam is a dog trying to cater to the needs of SD. Ford stuck it in the Explorer 5.0Ls even though the Explorers were all MAF and could've easily run a better cam. My guess is they were already fighting emissions issues hence the GT40p heads, and this cam was far more emissions friendly than the stock 89-95 GT cam or the 93-95 Cobra cam.

The good news for those looking for upgrades is the Crane 2020 and the Comp XE258HR are both SD-friendly. The more aggressive versions 2030 & XE264HR are NOT SD-friendly, but are much more idle-friendly than the E303 on MAF-systems. There's a guy named Randy Malik, owner of RM Comp Racing, up north somewhere that sells his own custom Windsor cams that he developed specifically for Speed Density F150s to boost their doggish performance with zero computer retuning and has had great results with it. The only adjustment required is some fuel pressure tweaks using an adjustable FPR. The cam even works with stock rockers, but he highly recommends aftermarekt springs/retainers/RRs purely due to the aggressive ramp rates on the lobes which is part of why it performs so much better.

But if you already have a cam, then it's all a moot point. What cam does he have you setup with? Brand/PN/Specs? I'm just curious what other SD-friendly cams are out there that are worth the money. But yeah you should be good to go with either GT40 or GT40p heads AND a cam upgrade. The cam upgrade alone would do the 351w wonders, but the combination of the two will certainly get you going in the right direction. What I don't know is with head swap, intake porting, different cam, and headers, how well the stock SD-computer is going to tolerate all that. I'm sure it can be made to work. But hearing the headache experiences of people on the eectuning forum dealing with Ford's poorly implemented SD-system is not encouraging. SD-systems, in general, are every bit as capable as MAF. But Ford evidently didn't implement SD that well in their earlier computers and it's a bit of a headache to tune and get right as compared to other mfg's implementation of SD. The good news is I believe they did "fix" some of their mess with the later computers on the trucks, mainly because they ran SD on the early F150 Lightnings. But they quickly updated the Lightnings to MAF, presumably just because it was easier. I've long since given up trying to figure out why Ford did some of the things they did.

Anyway, good luck with it. Let us know how it turns out and where you end up on the head choice.
...Always Somethin'

89 Ranger Supercab, 331, ported GT40p heads w/1.6RRs, Crane Powermax 2020 cam, ported Explorer lower, FMS Explorer (GT40p) headers, aftermarket T5 'Z-Spec', 8.8" rear w/3.27s, Powertrax Locker, A9L w/Moates QuarterHorse, Innovate LC-1, James Duff traction bars, iDelta DC Fan controller

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Soul
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Re: WTB GT40 Heads

Post by Soul »

Btw found this figured you guys might like it

http://www.eecanalyzer.net/tech/docs/HeadFlow.gif
87 Ranger: Coast High Performance 331 kit 28oz balance, Comp XE264HR14 cam, 64cc 185 AFR heads, 1.7 roller rockers, Full manual reverse VB c4

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