Projects UBR/UER account mapping in SLA issues?

Hello,

I was wondering if anyone would be able to help me with a SLA rule.  We currenty have AA setup to map the UBR/UER account by class code.  That works fine, however, once we start interfacing eveything to the GL, the UBR/UER accounts are remapped to a different account.  I need the UBR/UER accounts to stay mapped by class code.  I wasn't able to create a SLA rule by class code due to the fact that we don't have access to update the Source Assignment list.  I need to keep the existing SLA rule in place because it contains other