The Stovebolt Site Forums The Shop Area Driveline Another 4.10 RP swap question

I was chatting with my machine shop today, and mentioned that I was going to swap out the OE RP to a 4.10 on my 3600 to get the RPM's down on the 235 (want to keep the SM420). He opined that these engines, even after a rebuild couldn't last with a lot of miles at 60-65 MPH. I mentioned that some of you guys were achieving +/- 2000 RPM's at 65 mph with the 4.10 swap (in hindsight I may have made that up)...and he questioned at 1:1 in 4th, a 4.10 would get you down that low. So I found a rpm calculator on the web, and sure enough at 65 mph, 1:1 trans ratio, and a 29" tire (I guessed 17" + 12" of rubber - check me on this guys) and I get +/- 3000 rpm's. I want to be closer to 2000. My calculator indicates I will need a trans ratio of .7 to get to ~2200 rpm's. I know John did the swap, but don't know if you had a tach John. Question - have any of you guys been able to get rpm's down to 2-2300 with tires/RP swaps?