Alright, I am getting lost here. The original disagreement was on why we have steel and aluminum push rods in engines. I read what you posted from the service manual yes. You are right that they do have aluminum on the exhaust side of some Vanguards, possibly the ones coming from japan but that did not say anything on why different material push rods are used. Which was the original question in the first place. I can almost bet that those push rods are not the same aluminum ones that are found in other Vanguards and modern VTwins. The reason why we have steel in the exhaust side of the ones that are manufactured here are because the steel will NOT expand as much causing a change in lash. Aluminum is ok to use in the intake because the temps do not reach 1,200 plus degrees. Everyone should check the manual...always! But, it is not going to tell you why we use the different materials. If it does... show me... Please...