Big change this year, with 2 valve heads only for Suzukis and Harleys. I guess the NHRA wants to make sure that there is nothing stock on a Pro Stock Bike, LOL. It should be an interesting year.
The prostock Harley is an all billet, one off design, that has no part or design that is taken from a Harley, other than being a 4 stroke V-twin. No part on the entire bike is stock or come from a stock bike, not even the decals. The Suzukis must run a stock case lower end.