I replaced my T case and it does not require dropping the exhaust. I looked into the 90s trooper T case option and found the low range is roughly 2 to 1 reduction. Our TOD case is 3 to 1 so you would lose some of the low range. If I’m not mistaken you would get a neutral position with the non TOD case that would let you fat tow the car with no damage to the drive train. FYI I do have a spare TOD case if you need one. It is used but I’m not sure how used. I bought it at a wrecking yard then I found a new one on line and opted to buy the new one.