Street driving a 2.5l YJ or TJ is difficult at highway speeds on hilly roads or areas where there is a lot of wind. Yes, going deeper in ratio may help but then you may catch yourself to be in between tranny gears depending on the road conditions. Other considerations for axle swap is wheels swap, parking brake setup, ds adaptability, steering setup, and shock/leaf perch setups.
Another viable option for axles is the D44 set from a Wagoneer. Since you are probably keeping the driveline as driver's drop (assuming you do have SYE for the amount of lift necessary for 35's), you should look for Waggy's from 80 and newer. Make sure you check the front axle housing and not get the vacuum disconnect like that you have now. Flange hubs are fine cause you can replace the flange cap with a manual lockout. These axles have a very low ratio available for the size they are - 5.89s! Put in lunchbox lockers. They come as SUA so you may have to change the rear leaf perch on the axle, but I'm pretty sure they'll bolt under the front. You will have to redo the shock mounts. Only issue is they are low pinion setup and not a high pinion like that of Fords. If you go with a Ford front for the high pinion, 77.5/79 F250s were leaf sprung and nearly bolt in SOA due to the 5/8" difference in layout. But these will be 8on6.5 lug pattern whereas Waggys are 6on5.5. The 77.5/79 F150 axle could work but it does take some extra effort due to the radius arm mount.
97 TJ SE lifted, locked and rubbered for fun
94 YJ SE stock, 225s, Trail Tested