[rusty2407]

i want to upgrade my stock heads to some gt40s. i have a cobra upper/lower intake and bbk shorty headers. i cant afford aluminum heads, unless someone wants to give them to me of course haha. but as far as iron goes what should i get. i hear theres a gt40 and a gt40p. whats the difference? and which one is basically just bolt on wiht out having to swap over a whole bunch of stuff (cam, rockers, springs, etc) id like to leave all those as is, just get a little better flow.

[haywood11]

alot better flow then E7 heads. the difference between gt40 and gt40p i believe are the plug placement. i believe gt40ps have angled plug placement

[rusty2407]

which one would have the same plug placement as the e7? i dont want to have to buy another set of headers

[93mustank]

Regular gt40's will........but the p's with 90 degree boots are no problem

[1989Gt.]

so you just need 90 degree boots.... and there the same really?

[93mustank]

Heads flow around the same.... p's have a smaller exhaust valve.....but have better spark plug design.....and smaller combustion chambers than than the regular gt40's

Stock for stock p's are the way to go

[rusty2407]

i have 90 degrees on my ford racing wires i believe

[93mustank]

I also have bbk un equal shorties

[Arctic Fox]

Originally Posted by rusty2407 i have bbk shorty headers. and which one is basically just bolt on wiht out having to swap over a whole bunch of stuff (cam, rockers, springs, etc) id like to leave all those as is, just get a little better flow.

BBK shortys work with gt40p's. And you should change the valve springs, no point using the old, worn out ones.

[rusty2407]

i could leave the stock cam and rockers in tho correct? and rods too

[91cobra5.0]

your bbk headers will not fit the gt40p's but will work with the 40's

[flattusmaximus78]

Wrong ^ Just put gt40p's on my build and I have bbk shorties no problems.

[gotn20]

I have some really nice perfect condition gt40 non p heads for sale. I recently got some world jr heads and switched. They sell for 400+ on ebay all day for non p's I'll take 300 hundred plus shipping if you want em. I need some tires lol.

[fogged306]

The p's are just the updated version of the GT-40's. They do flow a little better than the GT-40's but not by a whole lot. You can physically bolt any header to the p heads without a problem, but some people have had issues with burning spark plug wires, even with 90 degree boots, with p heads and certain shorty headers... and changing plugs will be a pain on some cylinders if you don't get the p specific headers, there are a lot of guys that have made their own tool for this very reason.

[93mustank]

Originally Posted by fogged306 there are a lot of guys that have made their own tool for this very reason.

A little grinder action on a spark plug socket...no problem

[93hatch]

Originally Posted by 93mustank A little grinder action on a spark plug socket...no problem

i was thinkin today that with just a lil shorter socket the job would have been alot easier, on the entire driverside we had to turn the socket with a wrench cuz you couldnt fit a rachet in there

[haywood11]

Originally Posted by flattusmaximus78 Wrong ^ Just put gt40p's on my build and I have bbk shorties no problems.

+1 i have the same also

[1slo5.0]

When talking "price" and "budget" with these heads don't forget to figure in surfacing the head, a valve job, valve seals and valve springs. You don't know anything about the history of these used heads when you buy them so those things should be done...or you can bolt them on and take your chances.