question about GT-40 heads

[oldfox]

Hi ,, I'm looking thinking of picking up a set of GT-40 heads.
Not the GT-40p If I run the the GT-40 heads on my 91 5.0 will the head bolts be to small and require the adapter washers?

I'm told that with the GT-40p heads that there may be a problem with the way the plug angle and the header. Is this true?

 

[xpkpremier]

Dont let the plug angle scare you, most aftermarket headers will work. You will need to use 90 degree plug wires. As far as the head blots go, I think they are the same as E7 heads, someone please correct me if I am wrong. Good luck

 

[myslo50]

if the gt40 heads are off a lightning 351 then you will need the washers to fill the space between the head bolt and the head.
if there off a 302 base motor then the bolts are the same.

just an fyi you will want to replace the head bolts with new ones. i for get the year when ford started using torque to yield bolts, and once they are removed you cant reuse them because the bolts get stretched .

 

[oldfox]

if the gt40 heads are off a lightning 351 then you will need the washers to fill the space between the head bolt and the head.
if there off a 302 base motor then the bolts are the same.

just an fyi you will want to replace the head bolts with new ones. i for get the year when ford started using torque to yield bolts, and once they are removed you cant reuse them because the bolts get stretched .

I'm doing a little boost I was going with 1133 fel pro MLS gaskets and
ARP studs. Sound about right?

 

[myslo50]

anything arp is better then factory replacement

i have waiting is a set of gt40p heads for my fox. im researching for a set of headers to put on mine, i just have to decide if i want to go long tube or short tube. p heads flow better than the 40 irons but either way, either head flows better than the e7 head.

 

[ReefBlueHatch]

anything arp is better then factory replacement

i have waiting is a set of gt40p heads for my fox. im researching for a set of headers to put on mine, i just have to decide if i want to go long tube or short tube. p heads flow better than the 40 irons but either way, either head flows better than the e7 head.

I'm in the same boat as you. I read a good article that did a header comparison on a stock H/C/I car and it was long tube vs shorties. The shorties actually made more power and made a little more torque. Seeing how a GT40 top end flow a little better than stock, I'm guessing shorties might be better. I'm going with the FRPP shorties, mainly because of cost and fitment.

 

[oldfox]

I talked to the machine shop that has the heads and they are the F3ZE-AA heads
I think that's a 93 cobra head. Maybe someone drilled them out to fit a 351 or something?
I can get these heads for $369 totally redone and ready to go and free shipping
I don't think I can pass them up.

 

[stykthyn]

Lighting trucks ran gt40 heads. There are special bolts that will let you use them on a 302.