After driving a couple hundred miles in the Camaro with the M22 and 4.11 gear I decided a couple things... First thing was the close ratio gear set, although fun, is definitely not utilizing the nice fat torque curve of my 496. Second thing is the obvious fact that 3,500rpm at 70mph pretty much sucks, especially with a 4.25" stroke.
Considering this I decided to go with a "wide" ratio Autogear M23"W" trans with a 2.56 first gear and pair it with a new 3.55 rear gear set. Really the M23W is not all that wide of a spread, certainly a close ratio compared to the Tremec TKO 600 I had in a different car. I went with this combination so the effective first gear would be the same as it was with the 2.20 first gear and 4.11 rear gear.
This was my first time setting up a 12 bolt rear end, or any GM rear end for that matter so I was a little nervous about it but think it came out perfect. Gear pattern looks good, ZERO runout on the carrier, and .007" backlash. Took me a while but I got the rear end set up how I thought it should be. The carrier is a new series 3 Wavetrac 35 spline unit and the gears are US gear. NO NOISE after 20 miles
The engine makes so much torque I think the wide ratio actually benefits the power curve. Much more manageable 3,000rpm at 70mph compared to only 60mph before.