Here's something I do on every build. Quite often people think that they have valve noise when they haven't - it's the pushrods rubbing the inside of the top of the pushrod tubes at peak valve lift. Imagine that the pushrod is parallel within the tube when the valve is closed then as the cam lobe comes around and pushes the lifter and the rod upwards, the top end of the pushrod moves away from being parallel because the rocker arm cup moves sideways to allow the rocker shaft to rotate and open the valve. Then of course it returns to being parallel when the valve closes again. It's an easy fix if you know someone with a lathe. I put the inner pushrod tube which is made of soft aluminium in the chuck and run a 5/8" drill down the inside for about an inch. What that does is open up the internal diameter of the tube and create much more space for the top end of the pushrod to swing side to side without any contact. It's more common than you would think even on stock engines and can make quite a loud ticking sound. You can see witness marks on the pushrod itself if this has been happening. Unfortunately I don't have any in the workshop at the moment to show you the marks. A couple of pics here to show what I mean ..

Here's before and after the inner pushrod tube has been bored ..

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Here we're looking down through the rocker support at the pushrod with a valve that's fully open at 0.630" lift which is a reasonably healthy performance cam profile. As you can see there's still plenty of room around the pushrod. Had the tube not been bored there might have been some contact here ..

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Club members can send the tubes to me and I'll bore them out for free ...