What's the weight limit on your lift?
I asked my vendor if I could lift my Duramax EXLB, pretty much looks like your sons, with my lift and they wouldn't give me a definitive answer. I'm thinking I porbably can, just as long as it's pretty much empty.
There's hardly a 2-post lift you can buy that's rated less than nine thousand pounds (9,000#), except for maybe those Max-Jack (sp?) portable lifts; I could understand, maybe even expect them to have a lower rating.
Almost all lift brands use the max rating in the model number, in some fashion, so if you see a 9, 10 or 12 in the lift's designation, that's usually the
thousands of pounds it's rated for.
While exceeding a manufacturer's rating would never be recommended, I can't help but think there's an extra margin of safety; if I had a vehicle that weighed 9,025 Lbs, I wouldn't be afraid to stand under it on a 9k# lift__assuming there were no cracks in the concrete around the base-plates!!
While on the subject of concrete, most of the popular 9 & 10 thousand pound lifts specify a minimum of four inches (4") thick. If you're building your shop and can plan the slab ahead, you can go a little thicker in the area where the columns will go. When building our house & detached shop four (>4) years ago, I had the builder make an eleven foot wide by three foot length (11' x 3') of the slab in each garage a full six inches (6") thick, just for an extra margin of safety. I had already planned where the lifts were to go, so it was an easy__and no extra cost__inclusion.
Here's the extra depth, picture taken the day the house slab was being poured.
And the same spot with the lift installed.
They did the same thing for the detached garage, but I can't seem to find the picture they sent me__we were 1100 miles away for most of the construction__showing the trough added in the back.
Less than a month after moving in, there was a customer's car hanging in the air, while I proceeded to outfit the back shop and work on the car, both at the same time!