SamDaMan (May 28, 2001 05:42 p.m.):
I was thinking about this, and I am kinda thinking you is absolutly right on not need converter - its 3/4 coverage, of the total of the 60X80 tisol heatsink, not 2/3 unless you mean that 360 is 2/3 of 640 err guess not anyway but...
all you need is two "T" pices of metal: 20 on lett up, 60 on right up and 60 going down. You could cut it from a hardware store "T" that is 60/60/60 or so. Just invert them and screw into the existing 60 mm holes and then put your 80 into the top 20/60 cross of the T. You need screws that dont go as deep into the 60 mm heatsing as the regular ones (your T things will be much less thick than fan that come with HSF) and a long machine screw / nut for the 80mm fan mounting.
Or you could get a "T" that is at least sq root of 12800mm long (80mm on diagnol lenght) in the top t part and have solit connection on 3 screws with one open
Or you could get two sq root of 12800mm single strips and and some washer = thickness of the metal and cross one over the other. That might be best..... use the washers on the "top cross piece" so that it is level when screwing down to the 60mm heat sink.
Then you put machine screws into 80 mm position holes with a nut. And you have 4 machine screws sticking up at 80 mm spots and just put the fan into that with nut or nut/washer. Or put nuts on the bottom, but that seems harder.