I had to double clutch my SM420 into high gear. I found that if I paused for an instant in neutral w/o the second clutching before continuing the shift into high, there was no grinding. The pause is no longer in time than the double clutch would take.

Also, my left knee appreciates it.

1948 3/4-Ton 5-Window Flatbed Chevrolet

34 Years. Now with a '61 261, 848 head, Rochester Monojet carb, SM420 4-speed, 4.10 rear, dual reservoir MC, Bendix up front, 235/85R16 tires, 12-volt w/alternator, electric wipers and a modern radio in the glove box.