The Saturn/Warn OD units are operated with a lever and are either in or out. They do not have any electrical components or free wheel capabilities. You can operate a BW OD unit using a toggle switch and a wire attached to the #4 terminal. You will also need to manually operate the pull cable for the OD to engage. This system is used by several contributors to this site. Be aware that you can cause damage to the planetary and other components by starting out with the OD engaged. You can also cause damage if you somehow back up with the solenoid engaged. I prefer the factory set up as it is so simple to leave it in OD and let it do it's own thing. Once you get used to driving the stock set up you can get 5 speeds out of it quite easily.
Fred

Last edited by rfs56trk; 10/02/2011 4:52 PM.
1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine