On my K6-2+ 533; today I reattached the IHS. I again used AS5 for the core (after having completely cleaned both the core and the shield) but this time I used Permatex Ultra Black gasket maker for the corners. All I want out of an adhesive for this application is for it to be able to hold the IHS on when I remove the heat sink (rather than sticking to the heat sink) since the clamping force of the heat sink does the job the rest of the time, and after letting it run Prime95 most of the day I swapped the cooler and the IHS stayed on the CPU. With AS5 between the IHS and the core, and between the heat sink and the CPU, it runs at 616 with the core voltage at 2.2. The smaller Socket 7 CPU cooler I was using wasn't up to the job, and it would CTD when running 3D Mark - thinking it was too low on the core voltage, I went as high as 2.4, but the problem persisted. So I put on a bigger cooler (a Startech Socket 370) and was then able to lower the core voltage to 2.2 and it ran flawlessly.
"A lot of times when you first start out on a project you think, This is never going to be finished. But then it is, and you think, Wow, it wasn't even worth it." - Jack Handey