I also found and bought one of these from a P&P. I bought it primarily because of the 8-lug semi-floating design. Mine came out of a 1984 E-250 van, so it is likely the same as the one you found (they are rare). The one I have has 35-spline axles. It is a c-clip unit.
I was going to use this D60 in a project Cruiser I am building, but I later found a 35-spline D60HD full floater and will use that. I will part with the 35-spline semi floater for a reasonable price if anyone is interested.