[cliff-1972]

I wouldn't go as big as a 850dp but a 750dp would be good.The 670 could be tuned in also,but would lose in the upper rpms.Vacuum secondary carbs take some work to get right.I have a 3310 750 vac sec I would get rid of also.I has been worked over with a secondary metering block instead of a meter plate.So,the secondary jet can be changed like the primaries.If the carb has a dead spot off idle,the acc pump needs adjustment or a larger squirter be added.First that should be done is set timing.Then adjust idle vacuum,metering block vacuum screws,with a vacuum gauge.After that is set then play with carb adjustments.The acc pump adjustment at WOT should be .015-.020 clearance.