I think Ehrenberg did a series in Mopar Action with a 500 cubic inch wedge. This was a 1969 Roadrunner. He was running 2.94 gears, and a Turbo Action Hemi converter. I believe the car was running low 12's. The big inch engine has so much torque it is easily able to overcome the tall gearing and the looser converter allows some rpm's at low speed. I run something similar to this in my 1968 Charger. While I don't have timeslips, I can tell you this is a fast combination and is very sweet to drive on the highways.
The "Bold Beeper" ran a 3.23 in an 8 3/4" axle for awhile. It ran "Mid 11s" with that combo according to them. They then pulled the 727 and swapped in a "Kiesler 4L60E" 4 speed auto trans. I don't recall that they ever had any gear taller than that 3.23 but I do recall that they had a 3.55 for a short time.
Personally, I have ran several ratios in my 70 Charger. I have a 440 based 493 in the car.
I loved the 4.10s for snappy response at low speeds but 3850 rpms at 70 mph made it a pisser for the freeway. I've ran 3.23s for road trips and was pleased with them for the most part. I went with a 3.91 when I installed a Gear Vendors unit. That was a great combo but the GV had a few quirks so I pulled it out and sold it to a Moparts member that is quite happy with it now. I currently run a 3.55, a 28" tire and an 11" Converter from Ultimate Converter Concepts. Aside from gas mileage, the combo runs and performs great. I'd love to install a 4L60E 4 speed auto from SST but I'll have to save up a bit to get there. Lower freeway RPMS are not just a matter of better mileage, it is also much more comfortable. Lower RPMs= quieter, less vibrations and less wear on the engine.
