Okay, I'm currently in the planning stage, trying to make sure everything will work together. This is where I'm having an issue. I have a 76 280z, so it has retractable seat belts that mount in the pocket on the floor, and to the strut tower. I want to do a 4pt roll bar, partly for chassis stiffness, partly for safety. I also want to maintain the stock seat belts for street use. The problem is that, as far as I can tell, the main hoop needs to land right where the floor pocket is. I don't see how it could go anywhere else.
Does anyone have a creative solution? I really can't think of anything, at least not anything that uses the factory 280Z belts. If there's a different 3pt retractable belt that doesn't need the inertia reel mounted in the floor pocket, that could work, but it would also need to mount to the strut tower, not the roof pillar like the earlier cars. The shoulder portion of the stock belt is connected to the lap portion by a rivet(?) that could be removed, so if a franken-seat belt could be done safely, I would consider that, but personally I think that seems sketchy.