5K Engine source?

[M Connors <mconnor@frontiernet.net>]

Hi.

Does anyone know of a decent used or rebuilt motor source for Audis?
Dilemma:   5K in pristine condition with a toasted motor.  Car is in
excellent shape and worth putting some money into.  Would like to swap
out the motor with a newer engine but am reluctant to go to a salvage
yard and "take my chances" on a used motor with 100K+ miles.  I imagine
freight charges will make this engine mail-order idea "cost prohibitive"
but thought I would pose this question to the list for ideas.  Thanks in
advance.

Mark

'82 Audi 5K-S
'86 Audi 5K-CS "being held in ICU awaiting donor motor"
'87 Audi 5KTQ
'90 Audi V8