gt 40 headsmuch more hp gain

[foss94gt]

(Gt 40 heads how much horsepower gain?) hey guys i picked up a set of gt40 heads yesterday from a junk yard for 125 (a pair) brought them to my freinds shop and he said he would give me 200 for them i was just woundering how much horse power i would be looking to gain if i put these on , i will be putting a e303 cam in to thanks (and they came off a ford explorer if that helps)

[stang1_27870]

if they came from an explorer, then you have gt 40 p heads. they have a smaller combustion chamber than gt40s, and overall flows a lil better than gt40s. i installed a 97,98 explorer engine in a 93 gt. you will need different headers because the plugs are straight instead of at an angle, so it will probably burn the plug wires up. i would also recomend 24lbs. injectors and calibrated mass air sensor. you will also need plugs for an explorer not a mustang. to make sure you have gt 40 p heads look at the front of the head i believe they have 4 lines,also a P on the top corner just outside of where the valve cover gaskets go, and also have gt 40p stamped on it somewhere. keep them have them cleaned and checked at a machine shop. I think you'll be surprised of the potential they have to offer for the price