[84GT Ragtop]

I'm in the market to buy a used Mach and want to ensure I don't get screwed buying a car with bad heads, piston skirts, or whatever. Let me ask these questions then, after ensuring I have this all correct -- someone correct me if I'm wrong here:

Based on what DanB has stated and repeated for our benefit, there should be no problems at all with the "9 thread heads" due to their cooling redesign, which avoids overheating and associated galled valve guides. But how does resolution of the guide issue resolve the tick caused by the piston skirt? Or is the collapsed piston skirt also caused by the overheating of the head? Is there any evidence anywhere that "9 thread headed" engines have the tick? I would assume NOT but can someone answer that?

From what DanB says, the "4 thread heads" can overheat and develop galled valve guides. This includes the blue strip heads too, since they're identical to the non-blue-strip head. CBRRIDER98 says he had a tick even with blue heads so what DanB says makes sense, since that's evidence that blue strip heads, being the same design as the originals, still have the overheating problem.

What I'm not clear on here is whether the galled valve guides and the collapsed piston skirt are two issues related to one another merely because of a 3rd issue (overheating) or if the valve guide issue somehow allows you to hear the piston skirt issue. It just doesn't make much sense that compression in Jerome's cylinder was the same before and after the head job, yet the noise was resolved. Could he have had only a valve guide issue, and not a separate piston skirt issue then?

Seems to me the piston slap noise would be twice as fast as the valve noise, wouldn't it? The piston is moving on BOTH the intake and exhaust stroke, but the valve only moves when opening/closing on whatever stroke the piston is on. Couldn't the source of the noise be proved somehow using engine rpm and counting the # of ticks in a given time?

rob