I measured the bore of the two NT cabs last week-
I'm talking about the opening itself, not the size of the mount, which is identical otherwise.
The old standard NT carb is 13mm
and the newer NT66 Speed carb is 14
1 mm larger opening just like adverstised- the jet is larger too they claim
the billet intake measures exactly 14 mm before extra reaming- My old one is reamed to 15mm
I have an old stock intake I'm not sure if I reamed or not that measures more like 15 on the opening-
It doesn't make sense to put a carb with a larger bore on an intake that still measures the same, the opening is still the same
except when, like the billet intake, it moves the carb closer to the motor-
that seems to make a big dif.
The billet really needs no extra reaming with a carb of 14mm bore, except on the engine side perhaps.