In 45 years of Triumphs, the nicest one is the parallel intake ports T140D with Mikuni flat slides I ride now...I also had a 67 TR6 than ran very nicely...It's my opinion a dual carb bike tuned properly and with a rider who know how to roll open the throttle properly, gives up nothing to the single carb bike at normal road speeds and is faster at high speeds..And dual carbs just looks better...
i just rode this T140D of tony's a week or so ago. it's fantastic.
don't listen to tony. he complains about bogging. he's way picky. his bike has instant throttle response, absolutely zero hesitation on the slides in normal to enthusiatic throttle openings. it's like a correctly-tuned harley-- open the throttle, boom. it's made me look really hard at the VM mikunis i've used for years, that always seemed so much better. until i rode this machine with correctly-set up TM carburetors.
and there's no reversion in his bike either, at least none that anybody but him could detect.