OK Scotty, here you go...
I measured from the rear floor overlap weld to the rear and the front holes, inside and outside, and fron the factory floorpan lip on rocker side of the pan. The measurements are a follows...
Outside holes... 17 15/16" and 28 11/16", both pulling from the rear lap
Inside holes...20 5/8" and 29 3/8" from the rear lap
Front holes..8 1/8" and 21 7/8" from the rocker side lap
Rear holes...8 5/8" and 22 1/4" from the rocker side lap
Hope this helps, and if you need clarification about anything, message back and I'll do my best to explain if I can!! Geof