I had a Eaton posi in my 10 bolt axle and it had the 800lbs red springs . With the Eaton you never felt the 800lbs springs and never chirped or barked on corners and it left long black stripes on the pavement
The standard Eaton posi had yellow 400 lbs but they also have green 200lbs springs
The reason I don't have the 10 bolt and Eaton posi anymore is I replaced it with Quick Performance Ford 9"
I have the Tru Trac in mine with 3.42 gears. I really like it. It's great at getting power to where it's needed while at the same time being quiet while navigating the parkig lot. Though I've only ever run this one and an open diff. I've never used the clutch type.