[pistonbroke]

Ronnie, Here's what I have experienced with unleaded gas and no hard seats. The exhaust valve will beat or burn the block or head casting away to the water jacket as I have seen personally on my Windsors. In the case of a flat head you will lose your valve lash as the block material goes away until the valve burns to the point you have no compression. That's the motor I was running in my 41 pickups fate. If there is a better way around this let me Know, as I've said in the past I don't know everything and listen well. Thank you all for the input. it is greatly appreciated, Tim