Not sure if anyone was aware of an experimental B-17 with an Allison V-1710. I had read this in a book titled Vs for Victory. A must have book for the Allison V12 engine enthusiast.

http://foxtrotalpha.jalopnik.com/the-prettiest-b-17-flying-fortress-was-the-xb-38-1619966937/1620992458/+ballaban?utm_campaign=socialflow_jalopnik_facebook&utm_source=jalopnik_facebook&utm_medium=socialflow