Help with replacement seats...
 

Hi,
I have a 73 Jimmy that used to be a hunting truck and therefore has no seat belts and will not pass inspection.

I'm looking for seats with built-in seat belts that I can install so that I can drive it safely and make it legal.

Does anyone know what years of GMC/Chevy trucks/SUVs will fit on my truck?

Thanks in advance.

The biggest problem I see with this approach is that the floors are not reinforced with this in mind. That aside, nothing will just bolt straight in without some kind of modification.

I would just buy a set of generic lap belts & bolt them into the factory locations. Your truck did not have a shoulder belt from the factory.

I agree with ^^^
If you want to put in a late model seat and reinforce the floor pan buckets from the GMT800 platform will work and have the integrated seatbelts. Specifically Tahoe seats from 1999 to 2006.
The GMT400 seats will also fit with very little modification,