This is what i do:
Import your 8.7 package into the evaluation branch.
Setup a tag for windows 7 machines using OS version = 6.1
setup a deployment task to deploy 8.7but select:
Has any of these tags: Windows 7 + W2008 R2 - (name of tag- this is what mine is called for example)
I totally forgot about tagging the systems, brilliant idea thank you!