Box rail mounting

I’ve got my old over the cab contractor rack that mounts to the lip of a standard box, that I’d like to mount on my tundra….except there is no lip of the box, just the rail system.
Does someone make some sort of attachment for the rails so the rack can be mounted or do I need to drill through the box?
I’ve been searching but keep finding mounts for ammo cans, that fancy pegboard looking stuff or shovel/hi lift mounts.
Thanks!

 

Got any pics? Most just sit on the top of the box rails, is that what your rack does?
Did the rack come off a tundra?

 

I may have worded it wrong, haven’t had a coffee yet.
Originally came off my old f150, it’s a universal fit with those little J hooks.
Hopefully the picture loads.

 

Ford boxes aren't square, but Tundra's are. With those brackets you should be able to 'C-clamp' those
brackets on. How far from Princess Auto are you? I think they sell that rack? They are an Erickson dealer.
I'm from BC too. I found it. They will have what you need.
1,000 lb Contractor Steel Truck Rack

 

the issue is that there’s no lip to the box on the tundra, nowhere to clamp.
I was hoping someone makes something that attaches to the tie down rails that run the length of the box.
Or I’ll have to potentially drill holes on the top of the box and use some fender washers to mount it.

 

You do have the plastic cap on the box rails? But I have a 2010 and had a 2007 both had plastic caps, but a
c clamp would easily work. I would put a piece of 1 1/2" angle under the rail, so the outer edge follows the
edge of the rack, and drill 2 holes and bolt it on that way so no holes need to be drilled into or thru the top bedrail.
My '07 was owned by a construction company before I bought it, they had a heavy rack but it left no bolt holes
when they removed it at sale time.

 

Just grabbed this from another thread on 2014-2021.

4 Pack Truck Bed Deck Rails Cleat Compatible with 2005-2022 Toyota Tacoma&2007-2022 Toyota Tundra &Wrangler Gladiator&Ram Rail System/ E-Track Rail Tie Down for Pickup with Deck Rail System.

Amazon.com: 4 Pack Truck Bed Deck Rails Cleat Compatible with 2005-2022 Toyota Tacoma&2007-2022 Toyota Tundra &Wrangler Gladiator&Ram Rail System/ E-Track Rail Tie Down for Pickup with Deck Rail System. : Automotive

 

I’ll have to take some pictures of the box when I’m not at work.
Was thinking maybe some strut channel nuts may fit, run some angle iron off that if it isn’t too wide.
Ultimately I’d rather just get something already made haha