Is there a truck bed cover that’d work with custom size space?

I have a 6.5’ bed but with my tool box on top I now only has 56”
My question is is there a bed truck cover that can accommodate custom size? I was thinking attach a retractable cover kit onto the tool box? Would that work? I was worry that I won’t be able to trim the track to the size I want.
There is tool box that have the retractable kit built in but it’s like $3700.

 

https://www.accesscover.com/toolbox/ ?

 

Just thinking out loud here. My Bakflip MX4 cover for my 5'5" bed measures roughly 56" without the forward most half-panel. If you could remove that panel, it would almost be the perfect length for your truck. I have no idea what's involved in separating the panels, but I suspect it could be done. You would have to cut the cover rails and re-located the mounting hardware, but I also think that would be doable. Getting a water-tight seal along your tool box might be a bit tricky, however.

Matt

 

On my '13 and '18 tundras I shortened the last panel of a soft trifold cover, worked great but won't fold up all the way. If I needed the open bed it came of in a minute or two.

 

Is there absolutely no retractable cover kit that’d allow you to trim the track to a certain length? The roll up access seemed cheaply made and probably not worth $600.