Pizote. I went with the same 33% guess when I built my genny and battery box between the axles on my 4 window shorty. I tried to find a driveway apron and an angle of approach that would hang me up--no luck in 15,000 miles so I guess I'm OK. Heleads, unless you do some serious off roading I'd think you'd be good sticking to the "Jeep Rule".
Jack