Glenda,
If you're willing to spring for a full rebuild, than I would recommend Metric Motors in Canoga Park, CA. They offer excellent service and their engines are top quality. They have a toll free number (sorry, don't know it off hand) so check with 800 information and give them a buzz. Hope this helps!
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Rgds,
Aaron Greenberg
MB technician
Precision Motorcars, Cincinnati, Ohio
'67 250SE Cabriolet
'77 450SL
'79 6.9 (SOLD)

'80 300SD
'85 380SE
'89 420SEL
'93 300E 2.8