Just in case you were interested in the Weiand problems my friend had...
The first blower he received from Weiand was the little boy 144. The bores in the casing around the rotors were not consistent. So the tolerance I think he said went from a .007 to a .003 at the back end of the blower. In any case, as the blower heated up the rotors expanded and seized to the sides of the casing.
He sent the blower back to Weiand, who decided to replace it.
The second blower:
Timing between the two rotors was off and the rotors would have collided had he started the engine. This time he got smart and took it to The Blower Shop who checked the bores and adjusted the timing, hard anodized the rotors, and teflon stripped them. This was all 2+ years ago, hopefully the QC has improved. Just thought you guys deserved a little heads up.