reason twin carbs work well is to do with the firing order of the six's -
when you divide the log into front(cyl 123) and back (cyl 456)
-effectively you have two 3 cyl engines.( 1st carb serving 1,2,3 and second carb serving 4,5,6) and why a divider where the orig single carb is to give the 2 off 3 cyl engines
ie with ford firing order 1,5,3,6,2,4 you have even intake pulses though each of the two carbs as the cyl 1 intake sucks though the first carb and then 120deg later the cyl 5 and 120 deg later back ( cyl3) to the the first carb and so on. so an intake pulse through each carb every 240deg
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note also generally thats how the extractors are set up ie cyl 123 and 456
the base model 60's 6cyl jags used twin carbs as above - and tripple carbs for the hotter models
of course tripples look sexier and probably give better distribution in the constricted log ford head
but on the tripples(to clarify with the triples these intake pulses are if you have separate carb/intake/runners per pair of cylinders)
the intake pulse spacing are different across the 3 carbs
( something like 480 and 240deg for carb serving 1,2 , 480 and 240 deg for carb serving 5,6 and 360 and 360 for carb serving 3,4) - if my scribbles are correct
if the tripple carbs are connected to the open log, then the log acts as sort of a plenum and will dampen/even out the pulsing effect out.
but at the end of the day 1 , 2, 3 (or even 4,5,6) carbs will work.
brett