Wanting to do 30/45/60° seats with a 3 angle tool. Valves are small, 1.050 exh and 1.150 Int. So how wide should I make the seats? Spring pressure is about 60# on the seat, rpm 7500 +/- 1000. Valves will be back cut to lighten and for flow. How does .045 int and .060 exh sound?