Thanks, Mark! I was thinking of a home brewed version of the kind of brake used on a SM 420, adapted to the second trans output on the doodlebug tractor I'm building. I'm planning to use a Turbo 350 driving a crash box 4 speed, mated to a 2 speed vacuum shift rear axle. If the "fingers and toes" count comes out right, that gives me 24 forward speeds and 12 in reverse. The driveline brake will be used mostly during PTO operation to keep the rig from creeping while running a winch or another accessory with the crash box in neutral.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!