Here is part 1, of the next video in my you tube channel series of building up the 409 Cleveland. This is my take on measuring piston to valve clearance. I did this video to demonstrate that there is a difference of measuring piston to valve clearance when you use a dial indicator, versus the clay method. The clay method, and results will be on next video. I discuss the unloaded measurement, of net valve lift using checking springs, versus the same net lift measured using the loaded method, with actual valve springs. Just something to think about, with changing cams, and wondering if you can with a bigger cam. No way to know for sure without measuring, but may help with preliminary evaluation. Interesting to see some deflection, and loss of lift with the actual parts you are using. A cam that may be close for comfort with a dial indicator, may be just right for the fight, using the clay/Loaded valve train method. Thanks for watching.