Different pulleys/brackets/belts setup and kinds for A/C or not applications

[Nacho-RT74]

I have been noticing still several doubt about the pulleys setups if you have or not A/C car, specially when you are changing the setup. I think is some important to clarify. Ill post what I have known along the years with dozen of pics.

I think BB and SB are same setups ( not same pulleys or brackets of course ), but I'll be posting what I know, about BB.

Crank pulleys:
-Forged crank 4 grooves to A/C cars
-Cast crank 4 grooves to A/C cars
-Forged crank 3 ( or 2, not sure ) grooves to NON A/C cars
-Cast crank 3 ( or 2, not sure ) grooves to A/C cars

Water pump/Fan Pulleys
- 73 and laters A/C cars
- up 72 A/C cars... deeper than the one above. This set up uses a belt pulley iddler.
- NON A/C cars ( no matter the year )... deeper than the other ones.

Alt Pulley
-2 grooves to A/C car
-1 Groove to NON A/C cars... 2 grooves one can be used on NON A/C cars since rear groove is located on same position

After know this another factor to consider what else you need is if your car does have the water pump housing lower outlet on driver side as earliers ( up 72 ) or passenger side ( since 73 )... Once you know this the belt setup is:

Up 72 A/C cars:
double belt running alt-compressor-Crank
single belt runing water pump-Crank-IDLER
single belt runing steering pump-Crank

Since 73 A/C cars:
double belt running alt-compressor-Crank
single belt runing water pump-steering pump-Crank

The change of the water pump housing outlet to passenger side since 73 made the steering pump sits lower, at same water pump height and then the posibility to run one same belt to water pump and steering pump and eliminating the water pump/fan iddler pulley. On earliers with the steering pump on top, this wasn't posible.

Non A/C cars ( no matter the year ):
-single belt running alt-water pump-crank
-single belt running steering pumpo-crank


So after know this you can match one or another to make your setup.

Only doubts I have right now is about A/C or not A/C steering pump brackets OR pulley. I think is the same, but on both, 4 grooves and 3 grooves crank pulleys the steering pump ALLWAYS meets with the front groove... so that's the reason of my doubt... maybe the difference is really on wich groove is eliminated on crank.

Alt bracket:
No matter the year, the NON A/C upper bracket and the A/C one are different. Non A/C are big, with a hole in the middle to get access to the water temp sender. This bracket bolts on the more ahead water pump housing bolts. On this setup, the alt fits on back of the upper bracket.

A/C alt bracket is noticeable smaller, similar shape. This bracket does NOT have the hole to water tenp sender since fist just at a side of sender, and use the deeper water pump housing bolts, one of them on back of heater nipples. You need to remove the nipple to be able to bolt. Since this bracket fits deeper, then alt front "ear" fits IN FRONT of the upper bracket ( between ear and spacer )

Lower alt bracket is the same to both setups, even there are two kinds... the standart curved one bolted on water pump housing an there is another one that have an extra bolting point, on engine mount bolt. This give you more firmness to bracket. both are perfectly interchangeable.

I'll be trying to post pics about soon.


EDITING: THERE ARE 3 GROOVES CRANK PULLEYS FOR EMISSION CONTROL CARS PACKAGES TO SOMEKIND OF AIR PUMP, SPECIALLY USED ON C BODIES