So back in about 1984 I stumbled across a Watson 39m1. Bolted to a sm420 in a 55 gmc 350. Was pretty neat. I pulled the setup and put it in a 1960 gmc k1500. Moved the t case back 3 inches. And put a short couple shaft in. That was about as nice as it gets in a 60-66 4x4. I had a 4 and 3. Later I put a chevy ho52 with 4.56. And a no spin in. Added winches up front and rear. All pto driven. And I hauled firewood. I have never found another Watson 39m1 mount to a 420 since. I sold that beast in 1990. It was parted out up in Idaho 10 years later... I wish I had that stuff.