The parts book shows 3 possible spring packs that were installed on '67 Cornet wagons.
The spring packs were unique to the wagons, but the main leaf was the same as used on Taxi sedans and all Heavy Duty packs except the Hi-Po cars (which got unique left/right springs).

170 lbs/in spring rate seems a bit high for a production leaf pack. For comparison, Direct Connection Super Stock springs were 160 lbs/in.

Standard Spring, with bushing
Station Wagon,
- 2 Seat 2585 638
- 3 Seat 2585 639
- Police 2585 644

Heavy Duty Spring, with bushing
Station Wagon,
- 2 Seat 2585 644
- 3 Seat 2585 645

Main Leaf, w/ bushing
Std. Station Wagon, Taxi: 2485 648
Heavy Duty, All except 426, 440: 2485 648