When I had our 5.7L 1500 Suburban, I tried many brands of tires. The very best was the Michelin LTX, LT rated, in LT245/75R16 size, which is probably the size your van came with but in the "P" rating instead of "LT".
The Michelin tires are very expensive. We now have a 2500 Suburban and I have been running General Grabber HTS tires in LT245/75R16 size (LT type). They cost about 2/3 the price of the Michelin tires and seem to work almost as well. They don't last quite as long, however. The Michelins usually lasted about 30% longer.
Steve
