I'd say you should measure, per your own intuition. There's a lot of variances in place (what the previous owner might have done, stretching/wrapping issues, other things that might make your driveline longer/shorter/out of alignment) so measuring will be your best plan.
Denis A. Baldwin
1991 YJ 99 Vortec 5.7L, SM465, NP205, 14 Bolt Rear, Dana 60 Front, 5.13 Gears, Detroit Lockers, 395/85R20 46" Michelin XML tires on 20" XD Wheels, Cherokee Offset Springs (10" front to back stretch total), Bilstein 5150s, 1in. BL, custom cage, Warn M8000, Double D Dash/OHC, 4Low Front Stinger Bumper, DirtWorx Rear Bumper WTC, Tube Fenders, Comp Cut, 1 Ton HD Kingpin High Steering and PAID FOR.