Little needles make big difference
Figured my car was running crappy because it was tuned to lean (previously too rich). Some backfires, overrunning, etc. And the idle was always bad - that is it would idle for about 5 or 10 seconds and then it would miss - kind of a hiccup.
Also I was getting some popping sometimes through the carbs, or a miss, at 4000 to 4700 rpm, And worst, it was kind of crapping out at 4700, not really making any more torque.
It had N58 needles and worn slightly oval nozzles. Put in N27's.
Just learning the SU's so it was a real surprise that putting some different needles and new nozzles would fix all that.