usually it's a mouse nest and the blower motor resistor card coming into contact. the blower resistors get super hot and can set crap on fire in a hurry.
sounds like it's time for a security system. even if it's just auto-on lights. I'm sure all your beautiful trucks have some sort of anti-theft on them, right? kill switch? no battery in them? trained robotic attack dog in the pass seat?
I hate thieves.
XJ shackles are shorter than MJs, so the 1" is likely the lift for MJs, and the 2" for XJs. ask them for a hole-to-hole dimension. divide the extra length in half and that'll be the lift to your truck.