Need some help with 67 C10 bed

[SilverGT3RS]

Hey everyone

I have a 67 Shortbed that has a pristine bed on it-except for the bed floor. Someone along the line replaced the OEM floor with diamond plate. It’s done nicely as far as overall fitment (nothing was cut or changed from OEM fit), but I’ve already started to remove it because 1).- it’s extremely heavy and is not bolted down securely plus they shimmed areas with wood etc.

2.)- I’m going with a floor that allows me to use 13” tubs for my new custom 11” rims on the back.

My main question is about the bed rails. The original rails are under the diamond plate, but they’re just sitting there. They aren’t welded to the floor, the bolts aren’t tight and are rusted, weird wood shims are in between them and the floor…it’s just a cluster under there.
Several suppliers for the new bed floor are telling me the bed rails are welded on the new floor and I won’t need the old rails.

Is this correct?