First off - I'd like to thank everyone who's posted here, and answered all my various PM's about where to drill, what kind of harnesses to use, etc. Really appreciate your patience & help.
Anyway, some time ago, I decided to go with Schroth hybrid II
harnesses - which don't have a metal buckle on the anti-sub straps - largely because I was used to formula harnesses. (more on this later...) I ordered this, but neglected to mention I was going to wrap the antisub belts, so had to call HMS and have them send over shorter sub belts & buckles, as well as the longer 3/8" eye bolts. Finally got those today, and had to get my car back together! I'm missing out on all the drives & awesome weather!!!
Taking the seats out, getting TiDave's bar, marking the seat, deciding to go behind of the support bar, using door trim to protect the belts from wearing against the edge of the support, etc - easy thanks to everyone who posted before. This has been covered pretty well already, so I'll just post pics of my work...
Unfortunately I didn't have anyone willing to sew a sheath for me, so I took it into a local trim shop to have them finish things off. Which they did quite nicely...
OK - fast forward to tonight - and I've got the sub belts, and longer eye bolts.
(yeah, I know - red on right. I eventually did fix this...)
Drilling the holes - a 3/8" drill isn't big enough, neither is a 13/32" drill. You need the 7/16" drill bit for the 3/8" eye bolt. (I had to make a Home Depot run.) Then file the edges, drop in an eyebolt - and don't forget the washers!!!
I put some loctite blue on the threads, and some silicon on the backing plate underneath.
So put the seat back in and tighten everything down. I'm not terribly thrilled with the way the harness fits... I think the formula harnesses had the buckles for the sub belts farther out from the center, so the sub belts made more of an angle out to the buckles, then looped around the shoulder belt blades. These don't seem to go out wide enough, but I think I still like this better than a regular 6 point with the metal on the sub belt.
A bit strange - the inboard shoulder harness has the cam on it - (if you think about this for a second, you'll figure out why this is... ) Not a big deal, I suppose I can put it in the cup holder when I'm not using it.
OK guys - again, I can't say thanks enough to everyone who posted pics & their instructions here. Hope this helps someone else.