twodogs, I have a manual that covers the 550 and 660 tillers. Any certain spec you are looking for? Maybe I can scan the pages you need and email them to you.
Specifications:
cutting width- 50 inches
tilling depth 1-8 inches
final drive chain No. 100 1-1/4 inches
gearcase capacity 1.1 pint
chaincase capacity 1.3 pints
weight (less slip clutch) 432 lbs.
chain defection should be 10mm or 3/8ths inch.
Both the gear case and chain case call for Deere GL-5 Gear Oil
Sincerely, Dirt