Here are some part numbers and prices if you are using a Van Tilt Column the 1972 Truck Tilt bottom lower bearing is the same as the Van. Turm Signal Assembly is different.
Lower Bearing, # 34-0847, (LMC) $19.95
Lower Bearing Retainer #34-040851 (LMC), $12.95
NEW CHEVY GMC VAN TURN (Ebay) $24.00
SIGNAL SWITCH DELCO,
Part Number: D6217