[RichardJ]

Never heard of a 3-groove Alt pulley. If I recall jegs may have the 2-groove.
For this 6 cyl application, the purpose of the 2-groove is just to guide the PS belt out of the way.

For the AC, I used a separate single pulley that bolted to the hub on the front of the balancer. I built this about 15 years ago, but if I recall the hardest pulley to find was the water pump pulley.

I never throw pulleys away. If I don't have what I need, I visit wrecking yards with rough measurements and pick up 2-3 that look close.

For me part# or application is more of a goose chase.