ACC V1.x is deprecated since August 2008 and no longer in circulation.
The only reason to continue using ACC V1.x is if you still have ASGs below V7.3, e.g. 7.104 or 6.303. There is a backward compatibility switch in ASG V7.x devices - they can still connect to ACC V1.x servers.
ASG V8 can only be used in conjunction with ACC V2.x, as outlined in the release notes of ASG V8.