CA007 CARBURETTOR

my 1960 viper has a 28mm concentric mark 1,and nick payton confirmed the size as correct when rebuilding the engine.Do you know the correct main jet size, throttle valve cutaway, and needle position for the above. I notice from literature I have that late vipers had a 26mm concentric, but Nick measured the inlet and confirmed 28mm. - David Leece 2/7/2006