Before grinding the seats, Teal had already measured all the stem heights. After the head had been thoroughly cleaned, he checked the heights again. The intakes were fine, but the exhaust valves were now too tall. Because this is an overhead-valve engine, stem height is critical. Teal ground the exhaust stems slightly to bring them back within tolerance. The extra height also put too little pressure on the springs. This was corrected by using valve locks that held the retainers 0.050-inch lower than the stock locks did.