Forgot one thing everyone had issues with, air filters!

You will clog it up each hour, lose your tune, and start pulling dirty oil in as suction pressure builds on the clean areas of the filter. You will need to run two pre-filters, and peel them off, 1 per hour. Around Hour two, slap two clean ready pre-filters back on during one of the fuel stops. Peel those last two off during the remaining two hours and you should be at the 4 hour mark. Most of the motors that went out during the one I did was from pulling that fine silt laden oil in, it eats plugs first, then compression drops. Trust me, most wont even think about changing filters, but they wont finish either. Anyone who has worked on a buggy after an hour long main always finds something that was close to going out, multiply that wear times 4, and its ugly. Obviously, all drivers will need to understand thoroughly that driving smooth as possible with reduced wheel spin is the goal.

Good luck.