TYM4fun, i have the 63 qt (I'm pretty sure it's that size) engel and i had to make my slides as low as possible to clear the hatch. It just barely does. It's perfect for me because i can open it inside the truck and it will just hit the roof but be open. As i slide the fridge out, it slides out just enough to clear the hatch.
However, this is my second set of slides. The first set i had, i liked a lot more. They had a lock function that would lock the fridge out and also extended a little further out than the current set that i just picked up at Home Depot. The old slides i had, i picked up from a computer friend that builds the network servers for a large bank. They all come with "rail kits" for the servers but they don't need them since there are usually rails already in the rack. So they just throw them away. I would still have them if i hadn't of lost some of the ball bearings out of one of the slides during the last Utah trip.