Mod motors tend to push/suck oil into the intake manifold (blown or not). When you put a blower on they move even more oil. Catch cans pretty much mandatory for blown cars. Oil reduces the effective octane of the fuel. We don’t know of any blower kit that comes with them, or even has the option. The Moroso is the best non $400+ air oil separators/oil catch cans we have come across).

You will end up with a catch can eventually. May as well get it right now at a discount.