how are the 833 overdrives???

The short tail shaft versions were in the mid 70's A-bodies and after that in F-bodies. The long tail shaft version was in light duty pick-ups and vans.

You can use a long tail shaft version in an A-body with very little extra fabrication. I have one in my 68 Barracuda. I had to fabricate a bracket that would position the shifter forward from the rear mount to the A-body position and you need to shorten the drive shaft. BIGBLOCKDART.COM has a nice diagram for the bracket.

340duster, I am surprised you aren't happy with the around town cruising. I know I have 3.55 gears but if I am above 40mph it's in 4th and below that down to crawling speeds it's in 3rd. I only find a need to use 2nd if I need to make rapid acceleration and 1s is only used to pull away from a stop.