I have labelled the pic as i found my long stored parts. Think I am correct. I did read a very long time ago of a fellow who used hydraulic push rods for solid lifters and had a failure. The solids have a marginally larger oiler hole each end, they are also alloy so bend easier ? or harder to bend? than the mild steel ones of the hydraulic. Subaru Australia say that only solids were in engines of vehicles imported for sale here. We got hydraulics in import engines.

Having recently taken out my lifters they are definitely the solid one bottom of pic.

I just had to change several of my solid lifters in my 82 brat. As I understand it, the alloy allows a matched rate of expansion as the aluminum engine warms, minimizing heat expansion changing the valve adjustment. Of course, with the hydraulic lifters, the expansion is absorbed by the hydraulic automatic adjustment.