I switched to a 4.30 from 4.10 when i had a 408 and seen nothing on my slip. I did have a 8" Lupo convertor as well. I did pick up rpm at the strip thou which was something. Went from 6800 to 7100. Now need to put the 4.10 back in for the 511.
Several years ago when I had the 340 in my Dart I switched from 3.91's to 4.30's. The car averaged .006 better in 60' and carried it through the 1/8. There was no change in mph. A lot of money and work for so little gain.
At the time I was running a 9.5" converter from Edge Racing Converters that was built for the car. Very good converters for the money IMO.
