Whether you're installing a new column or just trying to tighten up your system, it's a good idea to replace the rag joint between the column and box.
These joints fit our 1967-1968 columns, but also be used to dampen vibration where two shafts are lined up with no deflection.
The joints have 1"-48 ends on the column side and 3/4"-30 on the box side.
1967-68 Rag Joing, 3/4"-30