I recently purchased the new Zenith rubber donut system and wanted to share a couple of observations.

1.  For those on the fence about the upgrade there are a couple of considerations.  If you haven't installed your Corvair engine mount yet, definitely upgrade before installing the engine mount while it's still about a 30 minute job.  I have about 15 hours on my Cruzer when the bungee cord failed.  I don't know why it failed I suspect it dry rotted during my 4 year 3 month build.  It's easier to replace a single bungee but I wanted to never have to go it again.

2.  If you are already flying be aware the upgrade will require you to remove and re-install the carburetor, battery and case, rear case alternator, and hoses for the oil separator.  This probably makes it about an eight hour + job.

3  I'm almost finished with the installation and the part quality and instructions were excellent.  Hats off to Zenith for reserving the right to get smarter.