8.75 Value?

Ok it's a 741 case, open differential but the gears are welded. I assume that's going to lock the differential? It spins fine. The gear is 2.91. I took the 3rd member when i bought the car because I thought I may use the gear for street driving but I've decided that I'm going to stay with the 3.70. Ok so that's what I have. As you can see I'm a noob at identifying parts!