gt40 head question

**92306gt** · 03-08-2008, 08:35 PM

what are the better ones, the p's or non p's?

**scott5** · 03-08-2008, 08:38 PM

from what i heard and read. the p's

**J-rod** · 03-08-2008, 08:40 PM

i thought the non P's were the better heads.....i thought the P's were the latter versions.

ive been wrong before though :)

**wick** · 03-09-2008, 11:59 AM

I thought they were both the same but you need different headers for the "P"'s.

**Killercanary** · 03-09-2008, 01:15 PM

GT40P's have outperformed the regular GT40's in every instance I have seen. They had a number of differences compared to the older GT40, but as mentioned the main thing was the positioning of the spark plug in the chamber. Here's some good data, scroll down towards the bottom to see the GT40 versus GT40P information. I've seen guys make close to and above 300rwhp in a few instances in 94-95 cars, so a fox should be able to do it with a little more ease.

http://www.jason.fletcher.net/tech/f...a/castiron.htm

**92306gt** · 03-09-2008, 01:29 PM

Originally Posted by wick

I thought they were both the same but you need different headers for the "P"'s.

i never heard this before. any other input on this????

**Killercanary** · 03-09-2008, 01:44 PM

Its true, you will need different "P" specific headers as the spark plug comes out at a different angle than all other SBF heads. Some regular long tubes work too.