My slicks are seven years old. I think it's time to buy new ones. I'm currently running M&H 8.5/24.5-15's on my SRT4/automatic LSD van. Should I stick with that size or maybe get a different size that could possible get a better 1/4 mile time? My van weighs about 3600 lbs and the last time I ran a 12.6 I was making 360 HP/460 ft/lbs torque. Last time at the dyno I made 386 hp/480 ft/lbs of torque. Since then I upgraded the intake and I am estimating very close to 400 hp. I plan on dyno-ing it again after I get my input shaft installed and before Roadkill's Zie-tie Drags in January.