Back on the road again! I ordered the replacement parts off Ebay, and the seller must have shipped them as soon as I ordered, because they came this morning while I was building the parts to fix the car.
I went to the big hardware store, and took the old pulley with me. Talked to a worker in the bolt department who helped me find some 4.5" long 10mm grade 8 bolts that had a shank that just fit through the holes in the pulley, so no slop. I also got 10mm nuts and lock washers. I cut the heads off, and turned down the last 2" on my Chinese lathe to 3/8" diameter. Then I threaded the 2" stub to 3/8"-16 NC to fit the balancer. Ran the studs in with Loctite until they came through the back of the balancer about 1/8". Then slid the pulley over the studs, and put Loctite, lock washers, and the 15mm nuts on the front. (Fortunately my pulley has plenty of clearance to go over the studs, and not have to move the radiator!)The pulley slid on with very little play in the holes, so it can't move at all, so the nuts aren't holding all the tension now.
Installed the belt, but since I discovered that gilmer belts should not be very tight, I just pulled the alternator over gently, and then tightened the adjustment bolt. Once I've driven it around a little, I'll double check tension, and the nuts, to see if the belt has snugged up any, and to see if the nuts are staying snug.
I'm still planning on looking into building my own belt tensioner from a modern serpentine tensioner, and run it against the outside of the belt, so I can run the belt even looser. I've seen a few on Ebay that looked like they'd be easy to build a bracket for, and mount between the water pump and crank pulleys to keep it tight. They sell new with a nice mount for about $15, so it's worth trying it for the investment.
I'm still surprised they don't send bolts, or instructions with these systems. Seems like maybe they don't know themselves, so they would rather omit instructions.

 

Wow that was a little work to create the studs. Would it have been possible to find a collar/bushing to fit on the bolts to take up the slop between them and the holes?

 

No, I only took about .030" off the bolts to get to 3/8", so there wasn't enough room for a sleeve. But some one could drill the holes out larger, and then sleeve them if they didn't want to turn them down.
They were a son of a gun to thread also! Grade 8 is pretty hard, and I wish I'd gone grade 5. And the info I got about these belts tightening up when they get hot is bogus too. We went out to the Wed. night drags, and I checked the tension when we got there. It was looser than when I set it cold, so it seems the belt softens, and loses tension as it heats up. Had my tools with me and reset it, so I'll check again tomorrow to see if it gets tighter as it cools overnight.

 

That sounds about right then. By the diameter differences, I came up with wanting a +/- .012 thick sleeve. I have thin aluminum sheet stock at work (printing plates) that would work for making my own. As much fun as you made it sound, I druther go that route as opposed to machining down and tapping the bolts. Besides, I don't have a Chinese lathe!

 

That's a much better idea too! Wish I'd thought of it! I have some thin brass shim stock that would also have worked well.

 

I sure am glad you're the one doing all the r&d on this belt setup! lol

 

Considering how long they've been around, I haven't been able to get any feedback anywhere form somebody who's had a set long? I found a guy on Hotrodders.com who posted about putting this setup on his Camaro over a year ago, but I PM'd him and he never got back to me.
One other note; if you go to this gilmer belt you need a really rock solid alternator mount. I had to really beef up mine with extra braces to get it solid enough not to deflect when the belt was turning. I have read on posts where others have had issues with alternators that weren't solid enough, and let the belt try to run against the flanged edge of the alternator.

 

I've seen a lot of stuff, but I don't believe I've seen this belt setup before you started messing around with yours.

 

I haven't seen one around my area either, but I have seen posts as old as 18 months where people talked of buying them.

 

Now that things seem to be back in order, I started adjusting my tune for the Falcon. Did some tuning and driving to check timing, idle air mix, etc. Wish I had a safe place to do a few short launches, so I could get a feel for how it launches. Hate to get to the drags later this month, and be surprised!