Notes about Chinese 2-Post lifts:
I paid about $2100 including shipping for a 11,000lb asymetric lift through American Lift Products? in Texas. It took about 16 manhours to install if you don't fry your hand in the process. It weighs perhaps 2,000lb, a forklift is a huge help with installing. Me, Robert, and Fred installed it.
Chinese instructions are nearly useless. You will need to buy 5 gallons of hyd oil since the cheap bastards didn't include any. Drilling the concrete sucked at first. Got a 1/2" impact drill from Milwaukee with a Vermont 3/4" dia carbide drill, and this was NOT the right tool. Returned the Milwaukee, and got a Bosch impact drill with Bosch drill bits and it cut through 6" of concrete in about 5 minutes a whole instead of 30+ minutes with the Milwaukee. Both the Milwaukee and Bosch were about $170. The Bosch will only use Bosch drill bits which are about $30 each, but one bit did 10 holes and still looked new, while the $15 Vermont bit was hosed after 2 holes.
Big problem is having the 3/4" redheads pulling out. Make sure you clean the holes first so the cement dust doesn't help the redheads pull up. On some of the holes we used cement epoxy to insure the bolts would not pull up, but that normally should not be necessary.
The lift can be assembled at two heights, max and max minus 4 inches. You will NOT need to go max height for a Duramax. I can walk under the truck and there is 1 foot more travel left.
It requires either 1ph 230v (two "different" 115v household circuits, no neutral used) or 208v (any 2 legs of 3ph 240v power). Wish it was real 3ph. Motor is a puny POS that is not likely to last a long time.