Okay, experts...I can't remember. In a Turbo 350 with a 28" tall tire and 4:11 gears in the rearend, do I use the green driven gear in the tailshaft? :confused: I'm having a serious CRS attack.

7 (6271537) PINK drive / 21 (3987921) RED driven (-1% error)

Cost is $8 and $11 at
http://www.transmissioncenter.net/speedometer_calibration_______va.htm

Local Chevrolet Dealer can order for usually $5-$6/each

Thanks a mil, Brian.