OK, time to get back to basics with this thing. The old "Box" dealio I described I only ever saw on old Jeeps, 'tis why I asked.
Someone made this thing run with whatever was available, and apparently did so.
First, and foremost, lets get the thing timed at TDC. Forget the dampner, I think that's an issue in this case. A silver Sharpie is going to be your best friend for this.
Crank the engine over by hand (reverse, tightening the bolt) until it's #1 is at TDC on compression stroke. Use a coat hanger, works fine. Mark the dampner. Crank it over again, BBC right? at TDC and watch #4 When it starts to drop, mark the dampner again. that should be, if I remember BBC's right, 8 or 9 degrees BTDC.
Set your dizzy pointing at #1 at that point you should be able to fire it and be damn close.
I could be wrong on this thing, been many years since I did a BBC. I know it works on BBF's using #6 instead of #4, but I think I'm right. They are very similar. Enginedoctor will chime in if i'm way off on this, but I think that's where you need to go.
Ray