Quik

when swapping to GTPs they will increase your CR about .5. they are about 58cc instead of the stock 62cc.

those heads out flow GT40s, out flow e7s this is with nothing done to them. they are alot more effeicent cause of how the plug angle is.

and using BBK shorty unequal headers isnt half assing anything. see reason you need specific headers is cause of spark plug clearance issues. there is nothing esle that is different. when you run bbk unequals you just need to run 90* boots for the plug wires

see what is all done to them then post back. i got about 600 total into my GTPs and that is port work, milled, valve job, hot tanked, fluxed, pressure checked. tfs springs, valve guides cut and the cost of the heads themself. granted this is a total price not what i paid.

give you a ballpark figure i paid for my GTPS and my GT40E intake $280. that was pushrods, rockers, head bolts, everything i needed off the top of the motor. it also included the coolant line and vaccum lines

blkgt50

The guy told me that they are stock heads. He didn't know what the cc's were on them. He had bought them to put on his stang but ended up selling the car before he could do that. I think that I'm going to pass on them because I don't feel like buying new headers since I just got some like 5 months ago.

wildstang87

OK, TO BE CLEAR, THE GT40P HEADS THAT CAME ON THE 5.8L TRUCKS AND SUCH LIKE THE 94 LIGHTNING ARE 64CC NOT 58CC. THE ONES ON THE EXPLORERS MIGHT BE 58CC. YOU DONT KNOW UNLESS YOU GOT THE CASTING NUMBER AND HAVE ACCESS TO FORD PART #S. THE THUMPERS AND THE POWERHEADS OUTFLOW STOCK GT40P WITHOUT A DOUBT. THE GT40P ARE MORE EFFIECENT IN KEEPING EMMISIONS DOWN, BUT NOT AT MAKING POWER. TO SUM IT UP, MORE POWER, LESS AGGRAVATION CHANGING PLUGS, AND NOT MUCH MORE IN PRICE, THE POWERHEADS AND THE THUMPERS ARE JUST A SURE DEAL.

Quik

now this is funny as hell. sorry a cobra,95-97 explorer and lightnings had GT40s!!!!!!!!! 97 1/4 to 01 explorers had GTPs. regular GT40s are around 64cc. GTP are around 58cc

with the increase of CR you gain about 15hp right off the back. for every .5 of CR rise you gain 15hp on a typcial 5.0 HO motor.
you can clearly tell a GTP head from a non. it clearly says GTP on it. so yes you can tell if its a GTP or not.

---replacing an earlier GT40 cobra motor heads with this casting will not only refine the power plants idle and purify its exhaust, but the further reduced in combustion chamber volume[plus increased exhaust port velocity] means that a bolt on power bonus can be expected too.

---ford systems engineer explained that the gt40p casting exhaust port flows so much better then the port in teh HO version that the larger Gt40 exhaust valve is not necessary.

---the GTP arrangement improves charge light off and combustion charge stability without creating additional turbulence

thats just some info on the GTP heads. and with these heads you will see a gain in power.

wildstang87

ok, you got me on this one, i was talking about the gt40s, not the Ps.