273, could it be a commando and CAM question?

Probably has a Crankshaft from a Late 67 - 69 273 or a 68 - 72 340 in it (although anything 273/318/340 would fit in it) Bonus if it's a Forged Crankshaft (some early LA 318's have the same forged crank as a 340)

68+ (late 67) have the larger register on the crankshaft. I've got a '69 273 in my '84 Dodge D50 pickup, with a hybrid transmission. A 1972 TF904 Small Block Case with the guts from a 1984 MA904 and the Torque Converter from a 1971 TF904 (slant 6, higher stall)

Didn't have to worry about the register size, due to it being a later 273 engine.