A 76AK/1AT or 276 AK/1AT in fact. The 1AT is the number for the sidefloat
Are you after the exact right one numbers etc, or just something close ? Amals come up on UK eBay all the time, but you need to search very regularly - although in perfect working order may be another matter.
Brand new ones are available these days, although for $$. But the value of having a perfect working specimen straight out of the box CANNOT be overestimated...
Someone like Martin Bratby in the UK could probably rebuild anything you find to be suitable - or maybe out of bits ?
1952 Mat G80CS 1953 AJS 18CS 1954 Mat G9B 1954 G80CS 1955 Mat G80CS 1956 AJS 18CS 1957 Mat G80 1957 AJS 30 1958 AJS 18CS 1958 AJS 31CS 1959 Mat G80TCS 1960 Mat G80CS 1961 Mat G12CS 1961 Mat G12 1962 Mat G15/45 1964 Mat G12CSR 1966 Mat G12CSR 1967 Mat G15
LH or RH Concentric is purely to do with the side the air and idle adjustment screws are on. They are often paired on a twin, so of course you want all the adjustments to be accessable.
In a Concentric, the float bowl is at whatever angle the carb is at. Enough angle, fuel goes straight down the throat, no arguments !
They sit flat on a Model 7 though, so no problems there. In theory they should be an easy carb to source and set up.
But no 2 setups I've seen quoted are quite the same. And the only one I've seen running was chugging black smoke, so I didn't take a note of its settings. ! Triumph fitted them to 500's in the late 1960s, so those settings should be close ?
When I have ordered Mk1's to replace Monoblocks, usually a main jet size of 20% reduction is the bench mark when fitting the Concentric. The 276 is a Pre Monoblock and would have to compare jetting between those two types to be anywhere near certain (some bike models were in production during the change over point, receiving a carb only change)
Mk1's seem to be readily available and components are at a very good price too.
Usually totally knackered though. And only rarely the right size/type for a Model 7 too.
It is of course possible to buy a brand new correct AMAL from the UK. All jetted right, and with correct numbers. $$ though...
P.S. Enfields in India use the Mikcarb. Cheap as chips. Usually jetted VERY lean, for maximum fuel economy - watch out. If you inspect closely, more 'restored' bikes have these than you would expect. I bought one to try - haven't got around to it yet.
Are you planning on winning races with it ? Otherwise an AMAL is an AMAL is a carb.
They all have their good points and less good points. The Concentric has a little strainer/fuel filter in the fuel pipe, which makes it less sensitive to rust dust or dirt in the fuel. (Which fuel tanks seem to be able to store up in nooks and crannies).
The 276 was original fitment it must be said though. Worth bearing in mind, for sale time down the road...