For what it's worth, I just converted my '36 Chevy pickup from 4.11 to 3.55 gears. It was a big project because the 3.55 gears from a '50-'54 Chevy car required use of a '37 Chevy car rear end but it's well worth it for the 15 % drop in RPM creating a much quieter cab where we can have a converstaion without shouting. The little 207 cubic inch engine still pulls a long 11% grade near my house easily in second gear no sweat.
