Need some help figuring out the actual problem
 

I have a 95 blazer and it's making a knocking noise and losing power. I bought a rod bearimg kit to see if that would help I go pick it up tomorrow and I replace them and I hope it fixes it but it might not. What else could be the problem?

Not many other things it could be, could be rod knock..

How does the oil pressure look?

Is there sufficient oil in the engine?

Are you aware of what's involved in replacing the rod bearings?

Tom, there is one way the OP may get lucky. I once had a car where the water pump bearing was going out, and it did sound like shaking rocks in a box.

Maybe that is his issue, and he can skip putting in the bearings, lol...