I clocked my Dana 300 as far as I could without cutting the floor. I then had to make a skinny front driveshaft out of thickwall 1.5" chromoly tube and it just clears the oil pan on the tranny. I could probably have cut the side on the oilpan and gained a little more space but it was not needed.
85 CJ7 4.3L FI/700R , 4:1 Dana 300 and 3/4 ton diffs.
76 CJ7 6 cyl/t18/Dana 20 pretty much stock
"It ain't been so easy but I guess I shouldn't complain,
I've always been crazy but it's kept me from going insane"