Hydraulic Lifters

[Matt MA]

I bought a JDM motor that had a bit of sludge in it. I've taken the head
off to inspect and clean everything up. It looks good so far. However, I
have a couple concerns regarding the hydraulic lifters and shims:

1. Can the lifters be permanently ruined by sludge? Or can I just clean
them up and expect them to work fine?

2. The FSM specifically says not to put the lifters on it's side,
unless they are soaking in oil. This is to prevent air from getting in
them. While cleaning and inspecting, I've had the head on it's side and
upside down. The lifters are still in the head. Are my lifters
compromised now?

3. If there is air in the lifters, I can bleed them according to the
FSM, which shows a thin needle like tool going into the hole in the top
of the lifter. What kind of tool is this and where do I buy one?

4. If I put all the lifters, shims, and rocker arms back in their
original positions, do I have to worry about measuring the shim heights
and possibly buying different size shims?

thanks for any advice,
matt ma . 92 SE-R