superstu23

ok heres the deal i have a 97 camaro z28 a4 and i recently had replaced the rear end the new rear has 3.08 gears ,i have a hypertech power programmer and it dosent have the option for that gear closest is has is a 323 gear setting so thats what i used i can also tell it the tire size though what tire size should i tell it i have to get the most acurate speedo reading?
please dont respond with get a mail order tune