Adapting a flatbed to a 1981 gmc 3500 / k30

[Trucksareforwork]

Hey everybody:

I have a 1981 gmc 3500 that I’m pretty sure was a cab and chassis. It has no bed on the back. It was a srw truck that has been converted to drw sometime in its life.

Question I have is this: I want to put a flat bed on it, but am new to that game. Can I generally adapt any aftermarket longbed sized flatbed to it or do I need to find one that is built specifically for this truck’s frame?

What do I need to know?

 

[Grit dog]

The answer is generally yes it’s not too difficult to adapt a flatbed to fit on a particular frame. But based on your question, have to understand, if you get a flatbed with wheel well arches, they need to be in the right spot. Or if you get one that is for a pickup truck which doesn’t have straight rear frame rails like your (and all c&c trucks) truck, you may be cutting or adding to account for the difference.
Also afaik, most all c&c trucks have the same or similar frame rail spacing so they are more universal for all the different types of boxes and bodies that are out there.

 

[Trucksareforwork]

Ok, I’m thinking it was not in fact a cab and chassis. I wasn’t educated on the topic and it sounds like c&c has flat rails. Mine has humps in the frame rails.

Any hints on adaptability of flatbeds to it?

 

[PrairieDrifter]

Ok, I’m thinking it was not in fact a cab and chassis. I wasn’t educated on the topic and it sounds like c&c has flat rails. Mine has humps in the frame rails.

Any hints on adaptability of flatbeds to it?

Cut and weld metal.. measure frame width.

Cab and chassis trucks are longer.

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[Grit dog]

Cut and weld metal.. measure frame width.

Cab and chassis trucks are longer.

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So apparently I was mistaken, squarebody C&C trucks also have a slight frame bump over the rear wheels.
OP, look up GM heritage center vehicle info kits. Pick your year of truck and the whole GM equipment manual is there including all applicable dimensions. You can back into figuring out whether you have a pickup or chassis cab.
Regardless, this is not a one size fits all modification. Find a flatbed that is the right length and width that you want and build the supports to get it mounted on the frame.