 Explorer GT40 heads, direct bolt on??
I have a set of junkyard heads from an early 1997 Mercury Mountaineer. These are the straight GT40s, not the GT40p which is fine with me since I have emissions hoops to jump through. I read somewhere that these heads need to be shaved to match their combustion chamber size with that of the e7 heads they are replacing. Any comments on this?
How about the OEM valves? When I had head work done on my bikes I was recommended to clean and keep the OEM valves as they will have the longest life. Does this hold true with the OEM valves in the GT40 heads? They only have about 65K on them and look fine (not burned, etc). | 
