Blower case scoring

At what point is it not worth a rebuild? What is too much?

I bought one for a little almost stock project I'm doing. The rotors look real good but the case has grooves in it.

I would like to know this also. Is scoring abnormal or common?

all 4 of my supercharger cases have slight scoring in them. Nothing to worry about really. they all make good boost. depends how deep the scoring is on your case though. If its THAT bad, then maybe consider going to magnumpowers.com and buying an mpx case. for 600 bucks.

I think I'll get some picsup.