8 1/4 rear end questions

The only way to tell if its a sure grip for certain is to lift both rear wheels and spin the tires. If they turn the same direction then its a sure grip if they turn opposite directions then its an open diff. To check the ratio turn the tires one revolution and count the number of turns the pinion makes. 1 tire revolution to 3.25 or so pinion turns - its a 3.21 to 1. For 200$ I wouldnt turn it down as long as it has the disc brake set up, these are getting pricey these days. Besides you can get alot of other scrap parts off it. If you get the 8.25 then its a great deal. You didnt have to do much just pay to get it dropped off, in my .02.

Best of luck with it....