my 26" tall tires do 2800 at 60 with 3.70 gears. that's with a 4 speed, not an auto. no, i didn't get that from looking at my speedo- i used a formula in The Auto Math Handbook. 3500 would be in the 4.56 area, for me at least. taller tires will lower the rpm, shorter will raise it.
1971 Nova(looks like 69 camaro from underneath!)
355sb, vortec heads, HOT cam,T-10 tranny, 3.70 gears 16X8" IROC wheels. 12" Corvette brakes on the way.
see pics here http://community.webshots.com/user/novaderrik
I have 4.10's now with 26" tall tires, I will go out on the highway and see for myself. I could have sworn I turn more RPM than that (when not in OD). I had a car with 4.56's before as well and I know it buzzed pretty high. Mine is automatic, so I guess that could be the difference.