Do not underestimate the little V8 60 HP engine. Many have been needlessly removed over the years in favor of the 85 HP and later higher HP Flathead engines. Richard Willim once told me that a 60 HP engine can be upgraded to 100 HP without that much effort. He also wrote a book on the 60 that has a lot of great information. You can order this book on this website:
http://www.willimvintageengines.com/
I also met a guy at a car show here in MD who built a Model A pickup for his wife that is powered by a little 60 HP. It looked great, sounded strong, and ran very well. A few pictures....