They need to be aligned with the pivot point. If not you are stressing something.

if everything is aligned, ot moves on the same plane. If its not your creating a triangle. Simple geometry.

I agree the mounts should be on the center line, but a number of them out there are mounted above and seem to be OK.
Guess the real question is how much of a triangle is too much.

One would have to assume IMCO has a reason why they list a tolerance of up to 1.5" above center line.

Mounting below center line is not addresses by the IMCO documentation. Maybe that's a definite no-no?

Rookie is the only one so far to reply with real world experience of misalignment. I would like to know for sure if his were mounted above or below center line. He mentioned using the old tab mounts which makes me believe he had them mounted below center line.

I called up IMCO and ask'ed about this topic. Their rep tells me they have jigs where different mounting geometry's are tested.
He assured me up to 1.5" above center line is OK and any distance below center line is definitely a no-no.

IMHO, there are multiple triangles rotating on different planes. The math is beyond me, but properly set-up jigs don't lie :)