Hmm that is interesting I never thought of it. I guess it's their way of saving money multiple fit items with the same machine setup. I learned my lesson on trying to save money! I just hope my valves and pushrods hold up lol. I'm looking at three different sets now I will decide on one and get it ordered. Its gonna be a few weeks tho im broke atm! I just learned im gonna have to buy a radiator too! Just great! Anyone need a kidney? I got one for sale! Haha!