Get accustomed to grinding gears, especially on downshifts. Synthetic gear lube is too slippery to let the synchronizers do their job with the heavy gears and the inertia involved with stovebolt transmissions- - - -SM-420's in particular. Use 90 weight straight mineral oil in the transmissions, 90 Hypoid lube in the rear end.
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!