Overdrive for V8s

[David C]

A brief update having done a few more miles with the overdrive 'box in the 410.
I replaced the redundant ammeter with an oil temperature gauge for the transmission. The finned deeper transmission sump seemed to help keep fluid temperature below 90 degrees when moving at any speed but when climbing hills at speeds below about 50MPH I saw over 100 degrees C.
I retained the 5/16" cooler hard lines and added a Hayden 696 Rapid-Cool Transmission Oil Cooler with Thermal Bypass in series with the original in radiator cooler. This allows the transmission fluid to bypass the cooler when cold and heat up fairly quickly. I don't think I have seen temperatures above 90 since it was fitted so seem to have got away with retaining the original hard lines.