are you sure?? What cars are you stacking??
I have the mustang convertible, and the Cobra. 120" ceiling. (right at 10')
It is smoother with the mustang on top as i then don't have to worry about the rollbar. But the Cobra is ok up there. I just make sure i pull forward far enough on the ramp to clear the rollbar. i have a 'few' (but not much) more inches i could raise the lift.
I haven't tried to do it with the 500 on top; or any car with a hardtop. That could be a problem.
I didn't move rails, or change my door, or change the controller/motor.
There are MULTIPLE threads on this issue, have you tried a search?
Don't rule it out yet.
Kristen
ps. can the lift post not be positioned deeper in the garage, to clear the door?
SSSammy has just installed a lift a couple of weeks ago, and i think he has a 'door' issue, too.
Maybe he could post a picture of how he resolved it?
oh Sam.... pics of lift, please??
edit to add:
Mustang on top. I certainly can't stand up under the car and work on it, but my purpose was to store 3 in the garage. I can sit on a stool tho', and clean.
if i put the '65 Mustang on top with the top down, (or even the Cobra) i could probably get the 500 under it. The 500 isn't particularly tall.
Hope this helps!