I go with no more than 4 threads showing on the adjuster. So I generally set my checkers to the two threads that CP suggests, and then see what the books have for premade sets that are within .020" of it. If you can't find any, go the custom length route. I dont like to make my own. I like to have sets complete...lol. also, dont forget you should be runnign the engine thru a lift cycle and cehcking the sweep on the valve tips with checking springs in place. If the sweep isnt good, adjust/correct the issue, then run it again. If it's good, then you have your pushrod length. Dont just tighten the shafts, then stick in the checker.