Swapping a sure grip?

I need to start putting together a new rear end for my dart. The stock 2.76 geared 7 1/4 is holding up but I don't know for how much longer behind my new 360, and the gears are killing it off the line.

I have an 8 3/4 housing and two 3rd members. Both are open differentials, they both need to be gone through and cleaned up before I could use them. I was wondering If I could swap in a sure grip into the case, as well as better gears. The 3rd members are 2.76 and 3.23 gears, I will go outside to see what cases I have. Or do I have to actually have a sure grip case?