Steering Column Shaft

I had removed the steering column from 1967 Valiant then modified the upper column for a floor shift but removing the shift arm, the gear indicator then fixed the lower column bearing. While putting the column back together, I realized the shaft was too short. I took hold of one end of the shaft and pushed on the other end and it moved a little. I then pulled on the shaft and it moved to a point it bottomed out. I noticed where the smaller shaft goes into the hollow shaft, there are two small holes. Are these shear pins? Can shear pins or metal dowel pins (1/16") be inserted. The shaft now measures 38" from castle nut to other end. Is this about right? Anyone know what the proper length a 1967 shaft should be?

Thanks for any advise.