carb manifold

[Mollbhan]

I have a 1948 mod 18, sent the pre-monoblock carb away to get re-sleeved and in the meantime bought a replacement pre-monoblock carb believed to be from another mod 18. The manifold seems to be too long and the carb cannot be fitted as it fouls the oil tank, as I don't have the old one here I cannot compare lengths, what's going on?

[Mollbhan]

Found the answer to my own query in the Amal reference catalogue, the 1948 mod 18 uses an 89B carb, I got an 89M carb which seems to have been used for one year only 1950 before they went back to using the 89B. Difference seems to be in the length of the inlet tract, just my luck, anybody need a 1950 carb?