R4 compressor nearly impossible to turn

[Demothen]

Just got some help to install my new AC compressor, before we installed it I thought to power the clutch and turn it over by hand. Could barely turn it. Tried the old unit and it spun easily. Going to return it, I have to assume it's garbage.

Can anyone suggest a good brand that might be available at a local parts store please?

Edit i should note that I did this with the lines uncapped, so it is not likely a vacuum/pressure lock. I cant imagine that it is normal for a compressor to turn that hard, I am sure it would burn up a belt