46" is pretty accurate (based on a quick measurement with mine up on the lift. I also have a 4 post with a 10 1/2' ceiling - not quite high enough to walk under the rails with the cobra on top, but I can stand between the rails underneath no problem. The mechanics chair comes in handy when working on the other cars that don't go as high too.
Since you're in NY, it might be worth a ride to DE to check out
http://www.gregsmithequipment.com/ - that's where I got mine - picked it up so no shipping nor tax! Also negotiated a better price than whats on the web too.