Sorry to say I just sold my Suburban. I got an offer I couldn't refuse. The GMT400 is my favorite truck platform. When I can find a rust free 96-98 Standard cab 4x4 454 5-speed, I'll be back!
I put that kit on my 6.5 burban. Descent quality but the muffler was way too small for my liking. Ended up putting on the biggest mid duty muffler I could find. Make sure all the connections have a good fit! The connection on the 2-piece tailpipe was a little loose and I really had to crank...
I have 285's on stock steel wheels. Only slight rub with wheels cranked and suspension flexed. Truck is 99' K2500 suburban with 6.5L. Stock suspension. Those tires came with the truck. When I replace them I'mm downsize to 265's
Try rockauto.com with your specific application. This is what I found for mine:
https://www.rockauto.com/en/catalog/chevrolet,1999,k2500+suburban,6.5l+v8+diesel+turbocharged,1353406,transmission-automatic,dipstick+/+tube,8486
The 6.5 is decent if taken care of and if the quirks are fixed. But they are underpowered compared to the other domestic diesels. I didn't care cause I love burbans