Old air is a very nice unit quality and because it had mechanical control options.
My Radiator guy said he experienced numerous electronic control failures from all the vendors.
I could have went straight through the firewall unit that Old Air sells specifically for the EB, but I had wanted to hide the lines as much as possible and keep them away from the headers.
I won't install another unit again period. My radiator guy told me they are a PITA, and he couldn't be more correct.