Thats a picture of the Sledpulling 101 class EEP is putting on for csevers! :-laf
Truthfully, even mild hp upgrades will make any single disc clutch junk in a hurry if you launch like you want to win.
3rd low with 285 all terrains, made short work of my two single discs back in the day. It takes a dual disc to have fun.
4th low is out of the question, 2 high is on the weak side of the transfer, and when 2 lets go in the transmission, it causes about $600 of damage.
1st high is slower than 3rd low, and helps the clutch live, but stock Fords will blow you away, lol.
With those gears, and a single disc, 3rd low is really your only choice, and yes, it is too slow to win most places.
If the track is good clay, I wouldn't worry too much about being at 8000 pounds, 75-7600 is plenty.