The good news is that the right brackets are cheap ($25-35) online for your YJ. I paid like $20 for mine used. I see them on eBay all the time under $40. You're gonna have more than a $40 headache if you try to modify the TJ mounts, I would think.
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.