Wiring Harnes & Vacuum Line Suggestions.

[placo1]

Engine: 1992 M119 5.0

In the next month or so I plan on changing the wiring harness in my car and was wondering if anyone has any tips/tricks to help make the job easier. I've inspected the layout of the existing harness and the only portion that looks difficult is where the harness passes through the firewall. Also on a few portions of the wiring harness I noted that Mercedes Zip ties were used to hold the wires together. Are these still available through MB?

At the same time I change my harness I plan on changing a few of the vacuum lines sitting on top of the engine. When purchasing these vacuum lines should I also change the rubber ends? The rubber ends look find and are completely pliable but I'm not sure if age will make them tear easily? Also would love any tips/tricks to remove install the vacuum lines.

Thanks in advance for the help!