Is this a correct unit for the quick ratio? Have 2 cars in the local yard with this code on the sticker in the trunk.

I thought the code was 9C1, i'm probably wrong

All my information indicates that the Caprice's with F41 or FE2 (1988-94), Police (1992-94), and Police w/FE3 (1995-96) were the ones with the 12.7:1 fast ratio gears. So no the FE1 should not be fast ratio.

The other way to know is if you can find the Alpha Code on the aluminum end plug or the aluminum side cover. My information says that they must be WZ, CP, FB, HL, CT, DU, TW, MX, or KW. All are fast ratio gears (if the Alpha Code is still distinguishable.)