2 Post Lift On Sloped Floor

I am installing a 9k lb 2 post car lift and on the back side of the base it is approximately a quarter inch off of the concrete floor due to a slight slope in the concrete.
2 post lift on sloped floor. Mohawk s a 7 model is an asymmetric two post lift with a 7 000 lb. 7 000 lb clear floor 2 post car lift. The base of the posts are 24 square the floor drops about 25 over that distance where the lift will be mounted. The problem is the entire floor slopes toward the center floor drain.
I have a two post car lift to install in my shop obviously the posts need to be perfectly vertical. The bolts are what hold the lift to the concrete. If the floor is perfectly level then by all means pay attention to the column plumbness. The a 7 also features a clear floor work area designed for free and easy access around your shop.
When installing a two post lift what is more important having plumb columns or frame contact pads that are level with one another. Most of our above ground lifts 2 post require 4 inch deep cement with 3000 psi integrity. Launch tlt240sc asymmetric 2 post lift. This asymmetric design allows mohawk s a 7 lift to fit in narrow 10 wide bays while all vehicle doors are fully opened.
Pure direct drive performance is matched by cutting edge technology and top of the line materials. Our clearfloor design offers enough space for cars and trucks up to 12 000 lbs. Economical high quality clear floor and floor plate chain over lifts with dual point lock release steel pulleys high strength equalization cables and double telescoping screw pads configured to accommodate the smallest cars to the suv s and trucks. The front side of the plate is flat on the concrete.
Can the back side be shimmed or should i use some sort of concrete leveler under the backside of the floor plate. Capacity two post lift clearfloor triple telescoping arms. The bottom line is this.