FYI i have been running months on end @ 4.75ghz stable. my load temp sometimes spikes to 60C, so i am definitely cooling limited. i consider this a very successful result and am very pleased. occasionally if i dont have my PC well ventilated during CPU intensive tasks it will crash, but this is usually me forgetting to turn my fans on high. i do think i could hit that 5ghz barrier with more cooling, but this is good enough.
thanks to everyone for your help along the way