I did stand on the clutch with the trans in 1st gear at signal lights while driving through small towns and the bunched traffic into / out of the Golden Gate Bridge. The rear end that came with the car has 2:45 gears, rumored to be out of a '72 or newer B Body. The engine turns at about 2K RPM at 65 MPH, and any uphill start takes a little more clutch work than I'm used to.
What 833 do you have? You probably could use a 3.09 first gear 4spd. they came in 64-66 sl/6 4spds, and I think some if not all overdrive 4spds. I would also suggest a 3.23 or maybe a 3.55 rear gear. That will help a lot in traffic and hills.