I had good response from the NBZT (thruxton needles) with various shimmings.
also, I recall that dynajet has a adjustable clip needle set for these carbs. I don't know what taper options there are.

05 speedmaster - 1100cc, 11:1 racing pistons, Carillo rods, thunderbike cams, ported and polished head, 2mm over intake and exhaust valves, Barnett kevlar clutch, scepter pipes, oversize manifolds, 45mm HSR's, TTP stage 4 firestarter