If you already have it do some more research before you jump into it. I bought a 66 Nova 10 bolt for $700 and paid $600 to get it narrowed. I should have gone with an S10 rear end as it is already the width I was looking for. Unless you’re going to race it I wouldn’t sweat it.
I have had a 3:73 S-10 with a posi in my Nova for 15 thousand miles after I did my Ls1 /4L60 swap.It also has a 285 tire.All I did to it was change the gear oil ,add a posi additive and add new axle bearings and seals. Previously I had a single track 4:10 S-10 under it for 10 years with no issues.If I happen to tear it out I will buy another one and let her rip.The S-10 Blazer rear sway bar that I added really helped the way my Nova handles.It in conjunction with the CPP front sway and Competition Engineering subframe connectors drastically changed the handling of my Nova.