heat sink stock is trivial to find. ones with channels for clips, and the clips themselved that attach
to the pin side of the chip are the problem
I'm trying to avoid the 3M adhesive mounted ones, which are also trivial to find. fyi, they are 42x42mm, a common chinese size is 40x40
It is possible to remove the adhesive mounted ones with a heat gun. This all started when I discovered
that they don't mark the processor type on the pin sides of the processor, and someone gave me
a whole box of 486s at random speeds and vendors
It seems to me that a Socket 5/Socket 7 heatsink is close enough in side to a Socket 3 that some have used them for 80486s.
However, I do remember that not all 486 systems used the ZIF socket with clip lugs. Some used heatsinks that clipped directly to the chip; some used headsinks that were secured through spring-loaded standoffs to the PCB. And of course, the "glued on" ones.