What it should be, only McCall knows. 10 degrees for an evap SH is probably in the ballpark. This of course is with the box at temp. The refrigerant type has little to do if any on what equipment SH should be. MP39 is a pretty good replacement and works well in most apps I've seen.
Officially, Down for the count
YOU HAVE TO GET OFF YOUR ASS TO GET ON YOUR FEET
I know enough to know, I don't know enough
Liberalism-Ideas so good they mandate them