All attempts at making Ventilation Holes in the Power Tower case have failed (My room is littered with dead and dying drill bits). However I've spent the afternoon modifying the 486 heatsink I bought. Before I had the new heatsink over the black lump that came with it. I now have the 486 heatsink clipped onto the board and PPC chip and all overheating problems seem to be solved for now. I'll se ehow it runs over the next couple of weeks before I think about boosting again.