For sale is an excellent Winters #8520A quick change gear set with 21 and 27 teeth.  This is set 20A and in a 4.11 ring and pinion rear end this yields a final ratio of 5.30 and in a 4.86 ring and pinion rear this yields a final ratio of 6.25.  This is a 10 spline gear and in excellent condition.  Thanks for looking and as always I combine shipping when possible.