How high do they normally sit off the roof? I heard anywhere from 5" - 10", I assume it depends on the brand rack itself. I see most have advertised height, how much more should I include for the mounting brackets? I noticed my 92 with the larger tires has some clearance to fit in my garage, but not a whole lot. I would hate to get a rack and then not be able to park in my shop - lol.
__________________
07 Powerwagon, pretty much stock besides Line X bedliner and dual exhaust. Quad cab, fully loaded (minus nav), etc
92 XJ sport, 33" boggers, 4.56 gears, rear locker, more to add
07 Arctic Cat 400 4x4, lockers front and rear, 2500lb MM winch
Mine is like 4 inchs off of the roof, I can fit into my garage, when i put the spare tire on i can fit it in the garage too, but the tire rubs. I just went and mesured, From graound to top of cargo rack on my set up it 6' 4'' to 6' 5''. Dont have spare tire on top to get that measurement.
It really depends on what rack you go with. Also than it depends on if you go with rain-gutter mounts or factory rail mounts.
For instance my Con-Fer rack is a 6" tall rack and sits 7" above my roof. My wife's Surco rack is a 5" rack but also sits 7" above her roofline as her mounts are different.
Your best option is to figure out what you want in a rack, and than find someone who's running the same setup and have them measure thier rack height for you.