overdrive opinion

[davischevy]

Originally Posted by HO455

A couple of points on the 700r4.
If your looking to maximize fuel mileage the 700r4 has an edge due to the lock up converter.
To improve the life span of the unit only shift it into overdrive on the highway above 45 mph for distances longer than a mile. When the transmission is continually shifting in and out of OD extra heat builds up to the detriment of the transmission. 700r4s are prone to hunting when driving in the 35 to 45 mph.

I have a friend that has a stock 72 C10 big block with 3.08 gears and a 700R4. His truck "hunts" the OD.

I had a 55 Chevy and a 65 Chevelle with 2.73 gears and a 700R4. Overdrive was absolutely Interstate only. I think 3.42 is minimum rear gear for an overdrive to operate properly. Especially with a small block.