BrandenZ

The answer is most probably yes, but we're talking about 18 gauge 1970's sheet metal here. Personally, I'm relying on my cage to pick up the slack. My goal was more air, fuel, and water-proofing it, and this succeeds in that department. Also, welding it completely takes proper servicing out of the equation without fully dropping the entire cell, which by the way gets veerrryyy interesting with no access from the top.

I'm just gonna put this right here: http://forums.hybridz.org/topic/113348-sparco-r100s-in-a-240z/ These worked beautifully in my 240z, with a rollcage, using the stock rails (slightly modified, of course). You get front to back movement on the rails, and recline from the seats. I used a 4 point (leveraging my cage), and have zero visibility issues. I love it. They're more comfortable than the stock seats, safer, have bolsters so I don't slide everywhere, and my harness locks me in, unlike the useless waist-only inertia reel on the stock belts. Re-doing this without the stock mounts or rails will give you way more flexibility on placement (for a cage) and also headroom (I'm 5'11" and it's suuuupppeerrr close with a helmet on). Buy sparcos rails, weld and drill, and you'll be good to go in no time. Edit: If you do decide to track or autox, these seats + harness make a WORLD of difference. I used to spend my right corners on the tranny tunnel, left on the roll bar / door, now I'm flat locked in and only focused on the next corner

Let me check on this the next time I'm at the shop. I'm 90% sure I still have a spare, working one of these when I thought mine was busted. Turned out it was just the relay. PM me and remind me if you don't hear from me by Saturday.

I've done this swap and can confirm all the points you've already made. The flanges are a direct swap. I didn't need a puller on the Z flange, I was able to slowly tap it out by working my way around it. I also used the same appoach Jthom mentioned, leveraging the workbench and the stub axles to lock it down. Good luck, and happy future 2-wheel driving!