When I bought my new wheels this year I spent a lot of time researching this as I didn't want to drill the wheels if I didn't have to !4 inch wide wheels, 14-32's slicks). I was told if I run tubes you MUST drill wheels or risk ripping valve stem out of the tube and wrecking the car. If running tube-less seal the sidewalls with dawn soap mixed with a little water. Clean tire bead with lacquer thinner, scuff inside wheel bead with red sanding pad and clean with lacquer thinner. install tire on rim and carefully brush "high-tac" sealer on bead. Inflate slick to 20-25 pounds or tire to 35-40 pounds and let sit for 24 hours if possible. Set pressure where desired and go racing. Mine have moved approximately 1/4 inch in 4 races. The shop that mounted mine took extreme care when mounting and I had very little clean-up but I did so with some brake cleaner sprayed on a rag. The way it looks I will never drill a set of wheels again. My 60 foots are in the 1.38 range.