10 bolt rearend posi question

[saon]

I am searching for a 10 bolt 8.5 posi diff for a car project I have.
I read that other model cars and trucks come with the eaton type (has the s spring and clutch disks) and some come with the gov lock which has its problems.
wondering if anyone knows if trucks came with the eaton type?
I know lots of trucks had 10 bolt fronts but I don't know what type they may have had.
did any vans come with the eaton type? I know they have 8.5 rears.
the year cut offs seem to be 72-89 for 28 spline and 89-94 30 spline. either will work for me I just don't want the weighted gov locker.
Thanks