4.10 GM 77-86 7.5" 2 SERIES GEAR (8620)Richmond Gear. Fits all 2 series carriers (original ratio of 3.23 and numerically lower). 7.5” ring gear diameter, 1.437” diameter pinion, 27 spline, 8620 alloy. Primarily for street, oval track, and lightweight drag racing applications. - LIMITED STOCK