Casting Number for 2.0 head?

Well I am fixing to be replacing the head on my B2200. I thought why not get ahead of the game and go with a 2.0 head too get rid of that annoying tick. I call up my buddy at the parts store and the company where he will get the head needs a casting to number to ensure its the correct head. I dont have access to a 2.0 head so what can I do too find a number so I can get my 2.0 head?

The heads are identical.

There are no casting numbers

The only difference between the heads is the valve train.