That cutter set is for .530 seals and the price is right. Not sure if your intake guides are already cut, but if so, measure them so you can make them all the same. They could be .500. To get the height right find out your gross lift at the valve. Cam lobe lift X rocker ratio if it is not a stock cam and you have the card. Cut a test guide enough to put a seal on the guide. Put a valve in the guide and put a seal, spring retainer and keepers on the valve. Measure from the top of the seal to the bottom of the retainer and add .060 for clearance. You can use a dial caliper to measure if you don't have snap gauges and mics. When you have enough clearance, measure the height of the cut guide and make the rest the same. Take your time and go slow so you don't go too far. Your cam may have different lift for intake and exhaust, so cut to the highest lift. I like metal clad viton seals, but any viton seal works well. I don't care for teflon seals, but they work too.
