CAT 335 F (CB2 linkage)

I am building a stick adaptor for a cutting unit to go on a customer's CAT 335 which they say has a CB2 linkage. I have the dimensions for a CB linkage but cannot find anything that distinguishes between a CB and CB2 linkage. The Pin Spread for a CB is 485 mm but there is a note in the documentation that I have saying that the Pin Spread for buckets over 54" is 512 mm. I was thinking that this may be what signifies the CB2 designation, but am not sure. I have called a couple different CAT locations and have not had any luck. One had all the same information I had, and the others just never returned my phone calls. Does anyone have this information, or know what the difference is between CB and CB2 linkages. Thanks.