AC add-on 1-groove pulley - which direction does it mount?
 

Replacing my front main seal and balancer... didn't pay attention to the pulley mounting when I took the crank and AC add-on pulley.

Does anybody w/ a 400 and AC remember what direction or can check their AC pulley? Because both sides aren't exactly alike. I want to say that the side with the convex raised center go against the balancer, while the side with the concave center faces the back of the crank pulley, but I don't know for sure. I know that it wouldn't be that big a deal to just bolt it down one way and check to see if the AC belt is aligned like it was before, but I'm just seeing if anybody knows off the top of their head.

Pic for reference:

Concave center:
https://i.ebayimg.com/images/g/OlUAA...uK/s-l1600.jpg

Convex center:
https://i.ebayimg.com/images/g/iAIAA...uJ/s-l1600.jpg

Yea I always have to look at it 10 times! Then I hope the paint is scuffed from the balancer side! I'll look tonight I have 2 in the garage.

Stack the two pulleys together (not on the balancer). One way will have a gap between the flanges and the other way not.

Have you had a chance to check? The balancer is installed and the car is ready to lower from the jack stands, this is all that's holding me up.

The side with the convex center also has the belt groove lip a little higher than the concave side.

Yes mine look like the bottom picture.