WmVCS 6.5 on IS6.1 - outrageous thought!!

OK, I want to try something wierd…

We have IS 6.1 SP1 box and a seperate 6.1 SP2 box. I want to use the WmVCS 6.5 packages on these boxes. Is it possible?

FYI - I know, you can install Deployer 6.5 package on IS 6.1 and the damm thing works!!