When I first had my Golden Flash back in 1975 I think it was fitted with a 376 1 1/16” carb. I have since acquired a 389/6 1 1/16”, a 389/1 1 1/8” and a mk1 concentric 1 3/16”. All have been on the bike a one time or another and all worked well enough except the concentric which made the bike hard to start but it ran fine once started.
I was thinking I’d fit a new carb which according to the Amal site is a 276 1 1/16” for my 1954 bike but then I noticed that the 60/61 Golden Flash was fitted with a 389/45 1 1/8” unit which is about £100 less expensive than the 276.
I notice that the inlet is 1 1/16” but easily taken out another 1/16”. Also the 389/1 in my collection is in good nick and with a few new parts would be serviceable.
First thing I’d like to know about is what do the Amal suffixes relate to? Also why is the 276 so much more money and is there any reason why I shouldn’t fit the later spec 389 carb ?
If you are not bothered about originality I’d go for a new concentric in 28mm, I think these are cheaper than monoblocs? And arguably a better design
and use the same jet sizes as the monoblocs (I’m fairly sure on that).
The 389 you have would be ok if in good nick and your cheapest option depending on what’s wrong with it, I had a 389 on my 56 A10 but with a fairly worn slide, so I bought a new 376 in the correct size of 1 1/16 which made it idle MUCH better and improved fuel consumption thus paying for itself, but any new carb would have done the same most likely.