Well . . . I hate to admit this, but you're right. I do need to rotate mine 90* CW. To verify, I even checked with my '66 go-to guy, Mike Crown. I also checked the alternator that I recently rebuilt for the '68 El Camino SS that I'm restoring and see that I've got it correct there. (You've given me some help on that restoration.)Greg, that's not correct. Looking at the rear of your alternator, the housing needs to be rotated 90* clockwise. This puts the flat part of the rear housing facing the valve cover which allows the alternator to rotate towards the motor further without hitting the valve cover, allowing more slack to install the alternator belt.