6.1 Hemi 69 Barracuda Fastback Father Son Project

And the winner is...
This is what I ended up with after drilling, tapping and installing an additional idler pulley to the center for the top span to shorten the span and pull the belt down and more out of the way.
By far the most contact area on each drive pulley with this routing.

There will be no belt slippage or belt flapping here.