Are you sure 75C is a correct reading? That's too hot. It's not dangerous (according to INTEL) but its still too hot. Get an extra case fan and direct it towards the CPU - that should help a lot. The best thing you could do is buy a really good heatsink. Surely you can find a decent heatsink if you found all that kick *** hardware already.
You're going 733Mhz on a factory heatsink? Now that's impressive.
P4 firstname.lastname@example.org dual R134A phase change chillers with 600watt thermoelectric array. Capable of -70F
Nixie tube numeric display control panel and pneumatic motherboard tray.