Trying to ID Straight 8 Crankshaft

[wdoftexas]

I purchased a group of parts recently that included a re-ground straight 8 crankshaft (.030) It was in a rotten old cardboard box that had 1938 40 series hand written on it. The forgeing or casting number on the shaft is 1296057 and GM B24 is also cast on the shaft. Would appreciate any help in getting a positive ID on this shaft.

[Muley Gil]

Sounds like a 248cid crank to me.