Change Manual Full Installs to GPO Host Install?

There are quite a few manually installed "full" installations of v12 on the network. I would like to deploy v13 "host" to all machines with Group Policy. Will the MSI deployment update and revise the machines that are currently installed with full to host? I am really hoping I don't have to manually touch all those machines to properly deploy these host setups.

Thanks for any info you can provide

Jason