On Truvativ stuff, I generally have to use a hex wrench with my 1 1/4" Craftsman combo wrench (it is like 18" long!) laced over it for extra leverage to tighten the non-drive crankarm. Anything less and the bolt will back out on me. It only requires a hex wrench to remove, no extra leverage.
Check the other thread "Crank Bolts", same response, different poster.