· I'm not old, honest...
Jana44 as in what gearset in what axle? 44 in a 30? You mentioned Rubi axles so that should already be a D44. Or are you talking about the Jana K4 putting JK gears into an older 44? (I thought all 44 gearsets were the same but I guess not) If you put good alloy axle shafts and Yukon Super Joints in a 44, I wouldn't hesitate to run 37's. Also with a Rubi 4:1 transfer case and 5.13's, 35's are too short. You will be geared too low in low range and won't be able to generate wheel speed.