[J P Stein]

Shop time for an A/C 9eleben motor rebuild is around 80 hours. That would be @ 100 bucks an hour or more. Why 100 an hour? Because 911 engine builder tell ya it is rocket science. It is painstaking but not rocket science. Anyone with a decent mechanical background can do it. For $8k it's worth getting some or using what you have. Parts ARE expensive tho.
Special tools are needed & likewise expensive. I bought them 10-12 years back & sold them recently for about what I paid new.