98 1500 Silverado with 15" tires....can I use 16 or 17 inch tires possible?

Your truck should be a 5 lug. Any wheel from and older full size truck will fit. Unfortunatly your lug pattern died once the next generation of truck hit. You'll have to go aftermarket to get a bigger rim size

you can go up to 20s if you want, it will all depend on the off set of the rim (spacing) so make sure you check. most places will tell you what will work if buying new? but used? just call a place a pretend you want to buy some from them and get your answer.... then you will be for sure on what fits with the proper offset. even if the rims need offset, for under 100 bucks shipped you can get spacers.

I went from a 15 inch to a 16 inch on my 98 Chevy c1500 no problem