So I have a 72 cutlass supreme, the previous owner worked at Oldsmobile,his goal was to make it a W-31? My crank pulley is bent and isn't allowing my A/C belt to stay tight. I ordered two crank pulleys which were a 3 belt, all were too small!

These are the numbers I pulled off the block and heads.
395582,409 147

It has a large crank pulley and a harmonic balancer. It is a dog on power,even with a HEI and 4 barrel.

It is labeled a 350 Rocket.

I'm headed to Las Vegas, Nevada 110 degrees from SlC,Utah 100 deg then across country to Townsend, TN!

I wouldn't care about A/C but my 2 year old gets too hot in the black interior!

 

Here are some pics

 

Is it a stock a/c or did it have a aftermarket one put in ? You should be able to tell by heater box , controlls ? Should be a letter config on pulley to tell you what it is also .

 

I'm not sure what you mean by "too small". Are you saying that the replacement pulleys are smaller than the one currently on the car? Where did you get them? I assume they are used? It would help us understand the problem if you could post a photo of the old and new pulleys side-by-side. To be honest, the photo you posted is a great shot of the PS pump and pulley, but not particularly helpful when discussing the crank pulley and A/C.

I will say that the block and head casting numbers you posted are correct for a 1972 350, and they are ALL called "Rocket 350".

 

The pulleys have a letter code on them. Look at our original pulley and see what code it is.