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Mark42 · 02-26-2010, 06:25 PM

forget about 285 35 17, no one makes that size.

The size I read people using here is 285 40 17. Its nearly the same diameter as the 235 55 16. Maybe the ls1 has different pcm parameters for calculating speedo? Either the base model has an incorrect speedo, or the ls1 has an incorrect speedo, because 235 55 16 and 275 40 17 are about 1/2" difference in height.

02-26-2010, 06:25 PM	#8
Mark42 Join Date: Oct 2009 Posts: 443 iTrader: (0)	forget about 285 35 17, no one makes that size. The size I read people using here is 285 40 17. Its nearly the same diameter as the 235 55 16. Maybe the ls1 has different pcm parameters for calculating speedo? Either the base model has an incorrect speedo, or the ls1 has an incorrect speedo, because 235 55 16 and 275 40 17 are about 1/2" difference in height. __________________ 1998 Firebird Coupe Mods: 3.73 Gears, Eaton TrueTrac, PCM Tune, LS1 Aluminum Drive Shaft, Cold Air Intake, 180 Thermostat, Magnaflow Cat-Back Exhaust, Moog LCA busings. My Firebird Projects : Click Here Last edited by Mark42; 02-26-2010 at 06:26 PM.