I just picked up a set of heads off a 2002 with 563 miles on them, (bad plug threads).

It feels to me thet the exhaust guides on one head are substantially looser than on on the other.

Does anybody have the recommended clearance numbers for both Intake and Exhaust?

 

Valve stem-to-guide clearance:

Intake: 0.0008 to 0.0027 inch

Exhaust: 0.0018 to 0.0037 inch

According to my Haynes F150(not Lightning specific but for V8 engines) Manual.

Dan