[rsavage]

I have a 70 Burb with 3.07's that I put a 200 4R in. For non-highway type driving, I don't use OD, just 3rd with a dash switch to lock up the torque converter when it shifts into 3rd. On the highway, the OD works fine. It turns about 1750 rpms at 66 mph on 235/70/15 tires. 3.73's would be ideal, I think, but your 3.08's will work if used as a 3 speed auto when not on the super slabs.