[Teds89IROC]

I swapped from 2.77 to 3.42. Just called chevy asking them which gears I need for the speedometer. They told me 15 tooth drive gear and 41 tooth driven gear. GM no longer makes them and I need to go aftermarket. I looked on the site that Bill posted up in my last post and the only drive gear to accomodate a 3.42 rear is 17 tooth, not 15. Is the stock drive gear in an 89 700R4 17 tooth? Also, what is overal diameter of a 275/40/17 tire? or stock iroc 16" wheel/tire?

~Ted