While I'm in the posting mood. Here is something different I did at the local track with very few rules in the flathead class. 5hp block, stock side cover, stock carb with only a exit bore check, stock 5hp, stock flywheel and the kicker "any head". I asked about the any head rule and I got a snobby reply, "ANY HEAD". So be it. here is the result. Only stickler was the stock 5hp valves. Look at the base of block under int manifold. You will see two stock valves protruding out of base held with set screws. They didn't say where or that I couldn't have extra valves. Deemed legal for the season according to rules as written by track tech man.