Rocker stand shims

[Calvin Krug <ckrug@laf.cioe.com>]

I happened to notice while disassembling the head on my MGB that there are
no shims under the two middle rocker stands.  Is this a big deal?  I'm a
little concerned that if it ran without them in place, it might throw
things out of alignment if I put them in.  What's the concensus on this?

Calvin Krug