Trans has 108,000 miles with a shift kit. Don't know anything about the shift kit because it came with the Jeep I bought. I put a 5.3 in place with a th350. I had no issues with the trans.
YOU ONLY NEED TWO TOOLS IN LIFE - WD-40 AND DUCT TAPE. IF IT DOESN'T MOVE AND SHOULD, USE THE WD-40. IF IT SHOULDN'T MOVE AND DOES, USE THE DUCT TAPE.
IF YOU CAN'T FIX IT WITH A HAMMER, YOU'VE GOT AN ELECTRICAL PROBLEM.