gt40 vs gt40p just a quick question

[94-5.0GT]

i know this have been cover way too lazy too look :sleepy1: but is there any difference in performance in them? Im looking at a set of gtp heads and wondering if there is a different, someone was telling that the gtp heads are better but i thought the gt heads had bigger valves? I already know about the plug issue on the gtp heads. also how much lift can the gtp heads handle?

 

[stang94X]

i think the valves are the same size, but the springs are different, ive always heard the p heads flow a little better but im not to sure on that

 

[Crone]

I asked something like this a while ago and I was told that the gtp heads flow better but the springs aren't as good in the gt40, so you would have to buy new springs. You could do a little pocket porting just to clean up the gt40's and probaly at least get a little closer to the flow specs, and you would even save yourself some money. :dontknow: I don't know this for sure but it's just what I was told a couple weeks ago

 

[LAFENATU]

Valves are different sizes as well as spark plug angle.

From what I know, you will need a GT40P header as the boot will sit on the header tube if you use a regular sbf 302 header.

Powerwise the difference is negligable. I like the regular GT40 head better myself, no bullshit with it.

GT40: 1.84/1.54

GT40P: 1.84/1.46

 

[wayne94mustang]

P heads work with ford racing shorty headers

 

[94-5.0GT]

i have bassani shorty but i heard that lt works pretty well or use certain plug wires(forgot which ones tho)

 

[BruhBrahBrad]

just get gt40's its not worth the extra hassle to me


btw i cant believe I have 447 posts on this forum. Im not even informative lol.

 

[94-5.0GT]

i want to get gt40 but i found a great deal locally for gtp so im stuck in a bind

 

[BruhBrahBrad]

WEll go wit the great local deal lol

 

[topless95]

yea but will the better deal also cover the price of new headers?

 

[rickzcobra]

Ok, hear we go.
List of headers that will work with gt40p that I know of.
Mac Longtubes, BBK Longtubes, BBK shortys(what Im using now for mine)

GT40p heads flow a notch better, the gt40 intakes flow slighty better than the explorer intakes.
GT40p and GT40 valve springs suck ass, gt40p are worse, max lift is .450
GT40p gives a little better HP also cause it bumps your compression .2
GT40p give you more of the torque feel cuse of the smaller exhaust valve(same as E7)

If you seriously are trying to make any kind of real power, forget both heads unless your doing some real serious porting.

 

[Mr.Bolt-on]

Yes, if your going to go with heads, just get a set of ported aftermarket heads. Might as well put the right heads on the car the FIRST time.

 

[LAFENATU]

All depends on goals. You can easily make 400+ with GT40/P heads with a supercharger.

I have a buddy making 430 with an edelbrock performer intake, GT40 heads, crane 2031 and a Procharger P600B.

 

[rickzcobra]

If your going for a budget build, gt40p cant be beat. Those heads make a world of difference from stock by putting them on and a good deburing and gasket matching the exhaust side. Done right with a nice intake and 1.7s, solid 60hp gain(of course with cai and exhaust.

 

[rickzcobra]

I noticed also you have a vert. Put a nice set of subframe connectors on before you bump up the hp at all!!!!!!!!!

 

[94-5.0GT]

bought some subframe connector just have to get them an also i will be getting new springs for the heads and probably let my grandpa do a port and polish job.

 

[rickzcobra]

Then youll be set. What cam are you gonna run. Just from personal experience, use either your stock cam w/ 1.7s and you will get a .474 lift or use a steeda #19 cam /1.6s and make .480 lift(both are max for valve to piston clearance). The reason is cause our 94/95 computers are so damn sensitive, it notices the slightest loss of vaccum, it goes ape shit and you wont be able to keep idle without it dying on you.
But very few get lucky and dont run into this problem.

 

[94-5.0GT]

i was going to get springs that can handle up to .550 lift and run a steeda 19 cam with 1.7rr

 

[LAFENATU]

Also...keep in mind that if you need to pass a visual emissions test - the P's have no provisions for internal egr or air injection via the crossover tube.

 

[94 DropTop]

Hey i noticed that there is no whole for the emissions tube on the gt40's i bought from you.