it is on a 64 impala, i ordered a 8.2" 10bolt pinion and ring but it does not fit, numbers on it are G2182 and GM3725899 if someone know what this is then i would apreciate the help

A 64 full size Chevy 8.2 rear end would need gears that fit a 56-64 pig style rear end. The 8.2 gears you ordered were probably for a 64 thru 72 Chevy II, Chevelle or full size car 10 bolt, or they may even be 8.2 gears for a Buick/Olds/Pontiac. They are not all the same and they don't interchange. If you ordered them from a catalog, go back and see if you can find gears listed for a 55-64 Chevrolet pig type rear end.