GT40's or GT40p's???

[Chietala]

I'm tryin ti find out witch one of these heads needs the least amount of fabrication to bolt up to a 89 5.0 motor.

I hear theres an issue with headers and smog with the P's. Is this correct?
If so does anything need to be done if your not in an smog state?

Thanks!

 

[SPEEDYLIFSAVR]

I have the p's . If you dont need to run smog then your good . the only thing you need to do is buy Ford Racing P specific headers which are sold on Ebay . Otherwise bolt em on and go .

What other mods will you be using in conjunction with the heads?

 

[Chietala]

Typhoon, B303 W/1.72s, have bbk shortys but I guess I cant use them??

Do you know what lift the stock springs can handle? Stock E7's bind around 510

 

[JBeezy53]

I'd go with either one. I have some GT40Ps that I plan on putting on my car but might sell instead. The only big difference to me is the revised combustion chamber on the P's, which causes the need for different headers. Valves are smaller on the P's but they ports have better velocity supposedly.

People have used BBKs with the P's and just modified their spark plug socket.

http://www.stangpro.com/html/articles/gt40p_files/gt40p1.htm

 

[JBeezy53]

Do you know what lift the stock springs can handle? Stock E7's bind around 510

I think more than .500" you can have problems with valve float.

 

[Chietala]

Whats the deal with the F3ZE aa's off lightnings and cobras??

 

[JBeezy53]

Regular GT40s. Don't have the revised combustion chamber but are "smog legal", they have the thermactor holes in the rear.

 

[Chietala]

So those are the best ones to get then?? Do they use the same springs as the stock E7's?? I know the lift on 93 Cobra cams are 479 @ 50.

 

[JBeezy53]

I heard that the GT40s have a different spring package on them that is good for a little over .500", I'm not for sure though. Maybe someone else can confirm. The GT40s also cam on 95-97 1/2 explorers but the CCs were larger.

 

[speed1972]

are you talking iron gt40's? they are prolly cheaper because you don't need the headers but I think you'll get more power out of the P's

 

[Chietala]

Yeah iron GT40's.

The P's flow slightly more than the norms but not enough for me to buy new headers to fit them.

 

[Foxfan88]

Ps have different ports and has a smaller exhaust. valve. they do flow a bit better but as stated before you have to buy special headers and if u have to buy them new then its pointless. I would get the regular gt-40s and save yourself the hassle. they will bolt right on like a stock head and be fine. and make good power.

 

[v8only]

well, IMO anyone buying an aftermarket head isn't going to run stock headers anyhow, so the point of having to run a different header is silly. In his case, he's already got bbk headers, so his concern is valid.

Keep in mind, the explorer gt40 heads have slight lower compression (probably not enough to make a big difference, my bro's runs like a raped ape) and the explorer gt40 heads don't have the smog bypass tubing in the heads either. Only original mustang cobra gt40's will have those.

IMO, get whatever head is in the best shape and for the best deal. If you come across some gt40p's, sell your bbks and buy some frpp headers they're great headers and will work with all ford smallblock heads.

FYI, the valve springs on the explorer gt40 and gt40p heads won't live past 5k and change, so changing those is a MUST. I used the tfs spring kit with my p heads.

As well, if you get original cobra heads, they've got the crane valve springs already, so they "should" be just fine.

 

[Chietala]

hahaha... the GTP pic iis killin' me! Way to stand your ground V8only!! lol

Well thanks for the input fellas I've got a couple bids out on ebay for a set of GT40's... Lets see if they quit actin' like these Iron heads are gold and I pick up a pair!

 

[DucatiRdr]

Try calling the local junky. I picked up my iron GT-40s for $200 and he wanted to sell me a 1996 Mountaineer GT-40 lower for $50 (which I might still grab).

Does anyone know for certain the amount the Explorer GT-40 chamber size is compared to the e7s?

 

[v8only]

hahaha... the GTP pic iis killin' me! Way to stand your ground V8only!! lol

Well thanks for the input fellas I've got a couple bids out on ebay for a set of GT40's... Lets see if they quit actin' like these Iron heads are gold and I pick up a pair!

lol, that was done early on from the excitement over having the heads.

I've actually just picked up an 82 notch, and I've got a set of iron gt40's from a 95 cobra, so I'll have both now.

 

[Chietala]

I tried that and the 14 yards in the north west Montana didnt have a pair.
I need to know exacty what cars they came on so I can search better. There not to familiar with what what Im doing so it's been really hard. I'm thinkin I might have to call back home to Sacramento to see If I can have a pair shipped. The only problem with that is they act like there gold because they know what we're doing with them.

So what cars do you know of?? Mountaineer's, explorer's, lightnings, cobra's... Do you know what years for the trucks??

Try calling the local junky. I picked up my iron GT-40s for $200 and he wanted to sell me a 1996 Mountaineer GT-40 lower for $50 (which I might still grab).

Does anyone know for certain the amount the Explorer GT-40 chamber size is compared to the e7s?

 

[v8only]

93-95 cobra's = gt40's

96/early 97 explorer's/mountainers =gt40's

97-01 explorers'-mountainers = gt40p's

 

[Chietala]

Sweet thanks!

 

[speed1972]

I found a guy out here in Denver that has a set of Irons for $175/obo. He's probably less then 10 mi from me. You might be able to get him to ship them to you or maybe there is a way to help out. I know how hard it can be to find a set....

check this link http://denver.craigslist.org/pts/265477343.html

I would even be willing to go check them out for you to verify they are truly GT40's and not P's

LB