With the larger tires, you not only want to look at axles but brakes too. The little brakes designed for 3000# Jeep on 25's is not going to stop the same with 36" tires on it.
Being a YJ, you can look for axles that have the similar leaf mount spread on the front to be nearly bolt in. Problem is, these will be full size or Wagoneer axles with the diff on the driver's side. If full size, they will SOA setup. Wagoneer will be SUA setup. Then there is the steering and its layout to consider (under/over knuckle or high steer), adapting the better brakes (master/vacuum), ds compatibility, wheel choices, and gear/locker choices.
You can keep the rear a 95-01 8.8 (Explorer/Mountaineer), or if you find a donor both matching axles.
Getting the axles in can take some configuration of spring perches on axles, shock mounts, brake lines (soft/parking), etc.
If you have plans for a v8, then I'd hold off now until you destroy an axle. Then learn from that, replace broken component, and look forward to your driveline upgrade. Jus take the YJ body off and place it on the donor's running frame.
97 TJ SE lifted, locked and rubbered for fun
94 YJ SE stock, 225s, Trail Tested