John, got a question for you, do you change out the exhaust valves to the Ferrea F6104 valve in a race version only or bare heads ? The reason I ask is that I have a set of Speedmaster heads complete with hyd flat springs { black Friday 2-3 years ago}. I will be changing out the springs, retainers for solid roller set and was wanting to know if I should upgrade the exhaust valves as well?