How to identify a close ratio to wide ratio 833

AHA!, Autocross
Now we know why the 3.08s
Are you running mostly in first? cuz that's got to be hard on the mainshaft.

2.66 First x 3.08 rear gear =8.19 final-drive. You could get a similar ratio with
1.92Second x 4.30s out back=8.26
This would help get rid of the lowspeed jumpiness or at least move it down. The minimum roadspeed with 4.30s might be 5.6mph

As to your tune, I'll tell you a secret. The jumpiness is much diminished after you get the t-ports synced, with a minimum Idle-timing.By "retarding" the timing from what almost everybody says you need, the peak cylinder pressure comes later when the piston is a little further down the bore.And it is weaker. So it is transferred to the crank a little more softly.And so the jumpiness is smoothed out by the heavy flywheel.
I ran the 292/508/108 for a while, a long time ago. I ran it with just 14 to 16 degrees idle-timing. It was still a little jumpy with 3.55s and a 2.66 low. So I tried other ide-timings, but that 292 was not happy about that. So I bought a dash-mounted, dial-back, timing box, and started experimenting. Soon I found out, that I could retard the Idle-Timing to maybe 8* when it got jumpy, and that would smooth her out enough to drive a little slower. Then, when the parade was over, I could simply dial the advance back up.
But that cam and I just could not become friends, so one day I had opportunity to sell it, and I couldn't yank it out fast enough!