I am not an Indian expert, though I wouldn't mind having a REAL Indian, from the late '40s or early '50s, just before they went out of business. I thought the Powerplus 100 engine was basically an evo design, that had some cosmetic alterations on the outside. I was told it was mostly S&S, Merch, Delkron, Andrews, and other aftermarket parts on the inside, and still used the basic Harley design. But Indian went out of business right after they came out with this engine, so there is not much information available on it that I can find. Peace. Jerry.