Long-distance travelling tends to wear me out so I always have a bag (or two) of sweets and either red bull or relentless.
Until recently, I never took breaks but the weekend of the Stafford meet, I'd done something like 500 miles and I was starting to have longer blinks. Twice I had to pull over at the parking spots on the A34 and take a five minute break.
I also always do something different to try to keep me awake, like turn the AC on full-blast cold for ten minutes. Then perhaps the radio for another twenty minutes, then back to CD. Then maybe wind the window down....you get the idea.
As long as your okay. Learn to recognise your limits. Dunno much about alloys but let us know how it turns out.