reducing ducting size queston

I tried the search but nothing turned up, so I'll ask

I'm setting up a new 4x4x6.5 tent for flowering, I'll be using a 600w with an adjust-a-wing reflector. I got an 8 inch vortex inline, but the exhaust ports on the tent are only 7.5 inches, which means I'll have to reduce the ducting. My main question is should I reduce in the inlet side of the fan or the exhaust? In my head it seems like the inlet should be reduced and the exhaust side should run as open as possible. I could be wrong, so I'm asking opinions on the subject.

well its really no difference. reducing the size of the ducting before or after the fan makes no difference. its gonna make the fan suck harder, or blow harder. (work harder to suck, or blow <--- more accurate?). just hook it up, turn it on and see if the fan motor heats up, if it does, the ducting is too small. and the fan is being overworked.