G'day Ron. I borrowed this from a Notrun site.
2 groved needle = PN 622/124 = 4 stroke
...used w 622/124 needle jet and 622/124 jet holder [600 series]
3 groved needle = 2 storke use w 622/079 jet, 622/080 jet holder
4 groved needle = 928/104, 4 stroke developed for 850 Nortons.
...used with stepped spray tube 928/107
Spray tubes
622/074 = 4 stroke, Cut Straight across
622/075 - 2 stroke, Cut at slight angle from oppostite side
622/123 = Trident, Cut at angle from mid point
928/107 = Norton MKIII special, stepped.
So can't say, would have to measure the taper (how long and angle).
Cheers