A518 46RH rebuild

So you just put it back (hopefully) how it was originally and called it good?
My original od piston was scored, so I replaced it with a good used one, that piston is discontinued, NA new anywhere except as a billet aftermarket piece. Big money.
I also replaced the piston retainer, which are available everywhere and quite reasonably.
So I'm not sure if my current setup sits exactly the same height as the original.
Had I not had to replace those 2 parts I would have probably just reassembled it "as was".
That spacer behind the thrust bearing is "selective" based on this measurement.
I got the new sonnax thrust bearing and spacer which came with a thin shim to go under that thick spacer if needed.