There's a hardback book that was put out a few yrs back by GM, which is now parent of Allison. I'm not sure it the book was ever in book stores, I bought mine from GM public relations dept. I've always been fascinated by the longevity & futuristic design of the Allison. I believe you're correct on initial production starting in '29, however I think I remember reading they started in '21.

Either way, the engine is 70-80 yrs old. Credit has to be given for the basic design. Compare it to what else was going on @ the time.....horses & steam engines? There were a lot of variants, but still "Allisons".