rearend upgrade

I am also on the fence.
I have a good 8 3/4 setup with 4:30 gears and sure grip (Detroit trutrac) I have a spare chunk with 3.55 but needs a new suregrip. I Blew the splines out of the nitro suregrip unit.
I have in the back corner a dana 60 that needs a sure grip unit but I have 4.10 gears for it. Plus i need axles for it.
I will probably get another suregrip unit for the 3.55s for a long trip to visit family someday up north. (8 hr drive)
But of the 8.75 ever breaks again I am going with dana

I run a 340 stroker with about 550 to 600 horse and an od passon 4 speed