1948 Sq4 basket job - help!

[nadab_sardar]

Worth sorting the pile in two steps. First, check the mainshaft case for the Sq4 mounting lug position, as Nev and Paul said. A single or twin case has the lugs in the wrong place, so that's the quickest way to throw out boxes that won't bolt up. Then check what's inside, since the internals and the speedo drive gearing can differ even when the cases look identical.

On the unstamped ones, Nev's right that some were probably spares, so the missing number doesn't tell you much by itself. Look for any casting marks, the clutch type, and the speedo drive, and compare against Roger's list. If you can post a few photos of the casings and the stamped areas, I'd bet someone here can ID them for you.

For the speedo, the part number is what matters, so I'd ask Paul about the Gauges and Clocks side. Since the gearing changed in January 1950, a speedo that suits a late 1949 or 1950 box won't read right with a 1948 one.

[Roger Gwynn]

It is the gearing in the speedo that is wrong 1947-49, corrected by new gears in 1950. The speedos didn't change so the speedo will read incorrectly 1947-49 with the correct gear, which is original. From 1950 the speedo will be more accurate.