Correct pulleys for a 1972 K20 with A/C, PB, PS, Airpump

[WhiteWhale]

I have a CA truck that I am having trouble with the pulleys lining up. As you can see I have a 3 groove crank and 3 groove WP pulleys but I think the upper is incorrect.



I checked my brothers 69 C20 which is also a CA, PB, PS, A/C, Airpump truck and his lower pulley is a 4 groove with the upper being a 3 groove.

As far as I can see:

first groove is the WP/ALT/Crank
second groove is A/C
third is Air pump
4th is power steering pump

Is the belt routing the same for 72? Is 72 also supposed to have a 4 groove lower? Anyone have pics of the factory setup and some part numbers?

Thanks