Taking the covers off to check timing isn't that difficult. Several screws are different lengths, so make sure you mark exactly where each one goes when you take them out.
If you have a 1g style adjustable CAS you should also check base timing with a timing light to make sure it's 5* BTDC. Several threads on how to do this by grounding timing through link. You'll need the lower timing cover on for this part.
Edit: or use this method if you dont want to set timing with the lower cover:
http://www.dsmtuners.com/threads/how...-cover.312350/
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