There's been so many carbs lately I'm loosing track lol - but as far as I understand it, that's the "Speed" carb and the "NT" the older version w/o the extra petcock...
TBH I've had both and I find the "Speed" carby no improvement at all over the NT, and in fact that extra fuel petcock a problem - as it's made of plastic & uses a lil perforated rubber washer, it degrades quickly due to the ethanol content in today's fuel and leaks profoundly - even if it doesn't it could end up interrupting flow as it swells... Mine just piddled everywhere lol
While it's easy enough to "fix" - there's no real reason to have a second shut-off in any case, I'd recommend finding one of the NT carbys... w/o the extra petcock that is
