Those OBS GM trucks have brakes that are almost criminally bad. Brakes on our 97 2500 suburban are no fun at all, especially when towing.
I haven't had any brake issues on my 06, but my newer GM truck has much better brakes. The 06 has 250k of the hardest miles you can put on a truck. I've pulled 12k loads, hauled 5100 lbs in the bed, just worked the crap out of it. It's only a 1500 with a 4.8 V-8. It still gets 18-20 mpg. My brother says the transmission should be in the Smithsonian
If you have a vaccum brake setup, either put a 99+ master cylinder in or swap to hydroboost. If you already have hydroboost, yeah your pretty screwed thats as good feeling as it gets. Also, whats the GVW of the truck? There was a light weight 2500 that used 1/2ton brake calipers, and a heavy 3/4ton that got the lightweight 1ton calipers. I've put steel lines, heavy 3/4ton calipers, 99+ master cylinder, and 99+ disk rear brakes on my 98 and it stops awesome.
No clue and at this point it doesn't really matter. The van I bought to replace it is just about ready so as soon as I get some paint on the roof I'm selling the suburban.