My 1 1/8 monobloc is 3" OA (flange to thread end)
On a related issue, for years I've been irritated by said monobloc. When I turn the fuel on it invariably floods out of the tickler leaving me standing in a pool of petrol. Usual remedy is to give the carb a smart tap with a spanner. I have looked into it several times over the years, but never seen the problem. Until today. Spurred on by another member's post about a similar problem, I looked at the inside again, and noticed the float got stuck when right down. The fault was the slight rib on the plastic float created when they welded the two halves together. It was binding on one of the webs associated with an end cover screw. Sanded the flashing off, and it clears nicely. Hopefully no more flooding. It only ever did it on fitst turning the fuel on. I figure that as I always run the bike out of fuel at the end of a ride, the float was resting on the bottom long enough to jam. Once freed, of course it was no problem until the next time. So much for modern materials. I presume they dissolve in alcohol as well, unlike the previous brass floats.