It's well worth the $$$ to get the tool if you're going to be doing your own setup. I believe you can use different measurement values and a feeler gauge instead of the tool but if you're subject to tech, where they will be using the tool, it's best to do it like for like. It took me a good 10 min of messing around with the tool to even understand how to use it on the intake side, I'm not sure how you're really duplicate that with the feeler gauge