I am getting a new computer chip burnt for my truck, which requires it to go up on a dyno. The guy who is doing it said that my 39.5" TSLs would throw the dyno off a lot being that tall. He said I should try to go for something smaller. What size should I look for? I have 4.56 gears, I can get my hands on some 31s, 275/60/R16/, 33s, 36 or anything else. Thanks!