Go to NAPA and order this seal,
https://www.napaonline.com/en/p/NOS11055, might get two because the bend real easy. It fits all GM manual steering boxes up to the '70s. Pull the pitman arm, and very carefully drill a small hole in the old seal just big enough for a screw to go into. Start the screw then pry out the seal with the screw. Pull out any old packing material, clean and replace seal. Check oil when done, wouldn't hurt to change it if it's still original. Most on here have real good luck using John Deere Corn Head grease, one tube is about $4 and is enough to fill the box. This grease is a 000 grade grease, it flows back to level after moving. DO NOT use any grease that is not 00 or 000 grade, gear oil works if the seals are good. Grease is thick and doesn't come out even with semi good seals.
Joe
