After driving both I like my 20r better. It pulls harder and revs quicker. The crummy little 20r carb on mine runs better at extreme angles than the 22r I had too. The 20r carb always seems a little rich and has a lousey idle most days, but you can put it vertical or on it's side and it still goes. My 22r carb quit when laid on it's side.
That's just my individual experience running both in stock form.
I'm sure other guys will chime in here.
If I were you I would set up the '80 for a driver/wheeler and cut up the '84 for a hard core rig.
There is just something better about driving a 1st gen...
