Good luck!!! Depending on the article, they say you will see 25-40 HP increase by just swapping to these heads (and that is from an E7 head, not a stock maverick 302 head...).
The aftermarket Ford Racing GT40 heads are aluminum, and there were a very few factory GT40P's cast in aluminum. One of the members of the Ranger Power Sports forums has pics of the aluminum "P" heads. The other 99.99% of the production GT40 heads are iron.
Somewhere around there. I offered $300 on my P heads, and the guy yanked them off ebay for me. I didn't want to wait and go through the bidding process, he was starting them at $200 so I offered to buy it now at $300 and he agreed. I paid $70 each plus $20 core (which I did not have), plus tax for around $95 per head for first set. This was a junk yard, with 1-year warranty. I didn't bother to get my money back when I ground into the water jacket... Second set guy wanted $300, I talked him down to $200 for the pair. He was a private guy off another forum. These are the ones I installed.
i just called, $40 per head but if i bring in my old '77's for a core it'll only be $30. im thinking i should keep the 77's tho as a "just in case set"
For that price, you cannot go wrong either way. In fact, I would buy BOTH sets and try to sell the ones you don't use for much more. Make a couple hundred bucks off them. Did the 99 Mountaineer still have the P heads?
http://i99.photobucket.com/albums/l299/Bluegrass_7/100_1400.jpg 40P heads, 40p headers but they won't fit a Maverick.
so whats better the P's or non-P's. sorry i only know my old stuff like my DOOE's and my 66 289 heads. any body got specs on these? valve size, cc's, ports. i grew up being told 14mm plug hole heads were low performance. but i just got a set of world product 351w heads w/ small plug and 2.02's so i want to learn more about newer performance.
AMEN BROTHER!!!!!:bananamanspark plug size doesnt matter much, combustion chamber, valve sizes, intake and exhaust flow and size matter im a youngster , and i preach C9 and D0 heads as i have a set on my car thats been worked over big time
Ps flow a little better, and have the spark plug placed more in the center of the combustion chamber, and have a little less cc (58cc, I think). The valves are much bigger than in older 302 heads. Then the P heads actually put in a smaller exhaust valve, but it still outflowed the non-P head due to the rest of the casting being more efficient. Ps are not desired by most of us because the spark plugs land right where the header tubes go, see below. These pics are of the driver side only, passenger side was almost unobstructed. You have to lift the engine, remove the header to do anything to the plugs or plug wires on the driver side, unless you use the special headers bluegrass mentioned, and they won't fit in our cars with the shock towers.
The Iron GT40's (not the "P's") are basically improved D0OE 351W heads. Same valve sizes, but improved port profile. In developing these, they started by flowing the old late 60's small block GT40 heads, then had Jack Roush do a set of E7's. The ported E7's out flowed the old GT40's. Then they went back to the drawing board and engineered the iron GT40's for production.
You're not really supposed to reuse these bolts. Some do, some don't. I don't. They're meant to be torqued twice and tossed in the scarp bin.
