7 1/4 Posi??????

"Used extensively in passenger cars beginning in 1972, the 8 1/4-inch housing also was used in 1971 and newer Dodge B-vans and pickups. This differential is a great candidate for upgrading many Mopar 7 1/4-inch rear ends by adding strength without spending a lot of money. Original passenger car ratios ranged from 2.45:1 to 3.21:1. The truck 8 1/4-inch differentials had additional ratios of 3.55:1 and 3.90:1. A fuel-sipping 2.24:1 ratio was offered in some 1980-'81 passenger car applications"