An Eaton works very well (lighter, smaller, cheaper, and more efficient than GMC 4-71 etc.) but the plumbing has to be doped out. Easiest is blow-through with just a filter to replace the TB, but you need to make a box to cover the entire discharge side and adapt to your intake. I've seen pictures (no details) of a 90° turn at the TB for a 4 bbl. adapter. The Eaton case can be rotated 90° or 180° to make plumbing easier.
Needs no external lubrication or drain.
Probably works with aftermarket 6 rib belt kits.
There are several nose drive lengths available so that the discharge window can be put (more or less) where you want it.
The Eaton M numbers are the charge volume of 1 rotation: M90 is 90" (about right for moderate boost on a slant), etc. and typically turn 2 to 3 × engine speed.
More of my comments on my site: http://victorylibrary.com/mopar/blower/blower.htm