A 2WD S-10 rearend is 48" backing plate to backing plate. A 4WD S-10 is 52" wide.
There's 2 different ring gear sizes for the S-10. '91 and up use basically the same rearend as an 80's Camaro or Firebird but S-10's are narrower. '90 and down are a smaller ring gear and weaker yet.
I have a V8 S-10 Blazer with a stock non-posi rear. It's powered by a 375HP/327 with a close ratio Muncie 4 speed and a 12" clutch. I have 9" wide rear rims wth 325/50/15 Goodrich TA tires. I've sidestepped the clutch at 6000 RPM a few times and amazingly it's still together.
I do already have a narrow Dana to install in it, as I don't trust that puney little thing in there now.
I'd listen to
RATNLUV about the Chevy C-clip thing. It's not pretty when you see your axle and tire pass you, cuz you know in about 2 seconds you're going to be in for one hairy ass ride.
Go for the Ford 9". Then you'll only have to install it once.