I just did this myself. Pulled seats out of a 94 to go into my 91. The risers and sliders are different but I got all of the parts so it should bolt right up.
Denis A. Baldwin
1991 YJ 2.5L, 1" BD MML, Ultimate 8.8, Super D30, 4.88 Gears, Detroit Lockers, 36" Super Swamper SAM-26s on Ion 171s, RE SOA w/RE1445 springs, Bilstein 5150s, 3in. BL, custom cage, Warn M8000, Double D Dash/OHC, 4Low Front Stinger Bumper, DirtWorx Rear Bumper WTC, Tube Fenders, RR OTT Steering and PAID FOR.