When I bought my '56 it came with a rebuilt GM compressor and a new condenser both still in the box. I talked to a Hot Rod air salesman on the phone who told me they would work with their evaporator. So I bought the evaporator, drier and hose kit from them.
I installed it all, adding oil to the compressor because the tag said to. After installation I charged it with the amount of freon they recommended. It would not bring the pressure up. It would not cool.
I called them and was told I screwed up by adding oil. They said I should remove the condenser and drain any oil out of it and they sold me a new TX valve and drier. Still no work.
I bought about 3 extra driers from them, drained more oil from the system. Still no luck.
They had me send the evaporator back for them to check. When I got it back it wouldn't hold a vacuum. They sent me another evaporator.
Installed it with a new drier. Still no work. Finally my rebuilt compressor burned up (lack of oil?) so I gave up.
I think I bought and released about 6 charges of freon, plus the expense of the extra driers and stuff. Their product sucks and so do their tech reps.