Which a/c idler pulley?

Need some help please. When I bought my 68 in December, the P.O. thought he had the a/c compressor and brackets, pulleys etc. I kept after him, but never got any of it. Based on the pics , can anyone tell me what is missing? Car was built 1/27/1968. Engine is 289.

Not totally sure on a 289 car as mine is a 390. But I believe it still uses whats called a lateral support. Bolts to a couple spots on the waterpump (at least the 390 does) and it will wrap around and catch two bolts on top of the compressor once in place. There is a adjustable idler pulley that bolts on the face of that support. Then there is a fixed idler that goes in the 1/2in tapped hole on the compressor base you have and the other end of the bracket the pulley is mounted to shares a bolt with the power steering support. Not sure if you need the top rod brace that goes back to the intake from the top of the compressor.
If you search idler pulleys and lateral support on WCCC you will see the pieces I am referring to.
If you want to run the type pump like Classic auto air sells so you can run R13 coolant I am not sure if any of the stock parts apply. Maybe?

There’s two styles the 68s may have come with:

Cast style:


Stamped steel style:


David, thank you. Much appreciated. I am fairly sure the big block set up is different, but I do not know for sure. My understanding is that even with the modern compressor upgrades, I still need the factory pulley set up. Plus it really bothers me to not have all the original pieces for my car :slight_smile:. I am also under the impression that my early 68 has a different set up than later cars.

Hopefully someone else has been there, done that and can chime in.

These pics are great! Still not sure what parts are needed, but this is very helpful.

Classic Auto Air used to have a catalog with exploded view diagrams to help identify parts. Looks like they spun off, or separated, the OEM side of business, so this might have changed. But you might try getting the catalog and see if it helps: https://originalair.com/request-catalog

I recently had to replace my compressor and my car is an early 68 (November) from San Jose plant. Here is a pic (for some reason it loaded sideways) of everything but the tensioner pulley that is pictured in one of the earlier posted pics:

what is the build date of your cougar? If you use the part / casting numbers from our site and copy them over to ebay you can score once in awhile.



Keep in mind every idler or tensioner pulley you buy needs a new bearing, here is the link for the how to video.


Thanks Don.
Built 1/27/68.

So it looks like I need a pulley that goes under the compressor, a bracket that mounts to the passenger side of the compressor, and some sort of adjustable idler pulley and bracket (plus a new compressor.

That sound about right?

So by the looks of Don’s site you need the cast iron lateral brace for a car built before 3-1-68
You need to use the C7ZA-8678-B adjustable bracket and pulley with this. Looks like this
Then the fixed idler pulley. I think it is this one and they just have the description date wrong. This is based off pictures above.
Then there is the specific hardware.
Might need to go salvage yarding to find what you need, or like Don said e-bay. We have one salvage yard up here in WI near me that I can still go pick my own parts. If I get there again I could check.
Otherwise the wanted board here to.
Were you giving away some window glass for a 67 at one time?