You can download the 3550 & TKO service manual at this link:
http://www.ttcautomotive.com/English...vice%20Manuals
But, don't think the manual is going to have the answer to your problems with vibration and noise.
You should check the driveline alignment as I'm thinking it's not supposed to be more that 3 degrees out of alignment. Pretty easy to do and you can search the internet for instructions. Thought I had downloaded some but couldn't find them.
Mike Forte is a good source for help and parts on the web at
http://www.fortesparts.com/ He helped me a lot with my install and has some unique parts that you might need to get the mounting correct.
Also, get some sleep