Short answer: Yes.
Long answer: It's not that simple, and the seat isn't the hangup. The belts don't have to run through the seat to safely hold you in place. the problem is the shoulder harness mounts. If you have a cage, you have a place to put the shoulder belts. Otherwise you're kind of screwed.
The factory belt is a 3pt for a reason. There's no structure to mount the other shoulder belt to. You can mount an aftermarket belt to the factory floor mounts, and the outside belt to the B-pillar mount, but the inside belt has no place to go. The roof won't work.