to "P" or not to "p"

[innes]

I apologize in advance for something that I’m sure was brought up many times.
How much better, or in HP terms are the GT40P over the GT-40 both off an explorer.
And both over the E7 heads. Take into consideration of NO serious porting or mods to them. keeping them mostly stock maybe slight mods.

Thankyou Billy

 

[JBeezy53]

You will probably not be able to really tell the difference between the P's and non-P's once either are on the car. The P's do however flow slightly better and their combustion chamber are more efficient. Stock for stock though the GT40s have larger valves. Both are better than the E7s.

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

 

[tylerrocks]

I've got p's. Never rode in anything with 40's or e-7's. they are ok, i really wish i would have gone aluminum...I will someday.

 

[bubba-dough]

This has always been a huge debate and I am not gonna get involved in one. If you can get the search to work (sometimes it sucks) you should be able to find all kinds of info. Just do what is in your budget or what the best deal is on. Remember that the P's take a specific header, well kind of.

 

[innes]

Yea I tried doing a search on this forum and the internet in general and its all mostly on the "P" heads I have a set of F3ZE GT40(not "P") of an explorer now I’m debating on maybe switching to the P heads I have FRPP unequal headers just not sure if there P compatible or not.

 

[spierce]

The P's flow better even with smaller valves than the GT40's.
The GT40P's if ported can flow as good as a set of GT40Y's (out of the box) but that involves a bit of work. Ported GT40's will not flow as well even if ported due to the shape of the combustion chaimber. Do a search on google for Porting GT40P's and there is a great article where the guy even shows his flow numbers.

If you are going stock, you'll still pick up a bit of power with GT40P's the GT40's make more power down lower I think but in the top end the GT40P's are better.

I have the GT40P's and I've ported them as much as possible and they are on my 351 and they make great power.

 

[bubba-dough]

Yea I tried doing a search on this forum and the internet in general and its all mostly on the "P" heads I have a set of F3ZE GT40(not "P") of an explorer now I’m debating on maybe switching to the P heads I have FRPP unequal headers just not sure if there P compatible or not.

The FRPP headers are P headers.