Newer Ram 8' bed with Extang Encore cover

Looking for a measurement on a newer Ram with and Extang Encore hard tri-fold cover, Part #62435. The cover I'm referring to has the opening front section that has the key lock. The measurement I need is from the top inside edge of the truck bed to the cover when the front section is fully opened including the small 3" section. I'm wanting to get a fuel tank toolbox combo that is about 30" deep front to back and want to see if I would be able to lock/unlock and open it with the front section opened.