The V6 Fiero and the Cadillac 4.9 both used a HR6 compressor. Here is the important thing you need to know. It is not a round 'O' ring. It is oval shaped. It is not a flat washer style. I went threw all of this while mounting the HR6 compressor in my 4.9 swap. I have removed the below and re posted it for you.
I only had one 'O' ring on my compressor. I spent about two hours on the net looking for a number to try to look up to get the correct ones. I located OEM # 02724674, which is AC Delco #1530169. I called O'Rrilly's in Huntsville, TX They had 9 in stock. 83 cents each. I drove the 32 miles each way and bought me 4 of these. If I was asking for these by application, 91 Cad Deville, AC & heating, compressor seals, etc they were not listed. I found this OEM number at
http://gmpartsgiant.com/This was a difficult item to find. I had been to 4 different parts houses trying to find these, I took my one in my possession, most said they had never seen one like these, as they are sort of oval shaped.
The guys at O"Riley's didn't even know they had these until I gave them the AC Delco number. This number was hard to find and might be helpful to someone else trying to AC their 4.9 using the Caddie's compressor.
[This message has been edited by josef644 (edited 05-18-2011).]
