1997 express G2500 came with 16X7" rims, not 15". Also site shows 6 lug option but spec is for 5 lug wheel. Never could find the offset for the factory 6 lug rim. It is my understanding that the wheels were upgraded to 8 lug late in the production run or possiby just for the 8300# gvw option.
2000 Express 3500 has 8 lugs... not 6.
...not sure on what’s the best / biggest / widest / maximum tires or rims will fit your car?
Write about the tires you are currently driving on.