If anyone has heard of gt-40p heads, could you tell me a little more about them. I have the chance to buy a set and want to know a little more about them. I have been told that they come off the explorer and need shortie "p" headers or mac longtubes. Thanks for your help.
Your right about them coming from late 90's Explorers. They out flow the GT40 heads installed in 5.0 Cobras. The flow rates are in the first thread of this forum. The are cast iron and identified by 4 bars at each end and they're marked GT40P on the castings. The spark plugs are at almost a 90 degree angle instead of a 45 degree angle.
I'm running GT40P heads right now with BBK unequal length headers. The only problem I had with the headers spark plug angle was with the left side. I had to flatten out one of the header tubes by plug #7 to get enough clearance. I bend my plug wire ends to 90 degrees also. About 4 plugs I must use a box wrench on the hex end of the spark plug socket.
I paid $350 for mine from a low mileage Explorer wreck. I see them on ebay often for good prices.
They're a low price performance enhancement for the 5.0.
I have them and I like mine with the P headers its a nice fit and its great bang for the buck I mkilled mine about .020 so it has a touch more compression