I've got a LT1 out of a 1994 Buick Roadmaster (with the iron heads). I am rebuilding the engine and I was lapping the valves when I noticed the exhaust valves in my heads were different on each side. The passenger side has dished exhaust valves and seats quite nicely with the head once I got a good lap on it. The driver side has flat exhaust valves and the mating seat is very small, even after lapping. I don't like the way the valves seat on the driver side and I was wondering if maybe someone has gotten to this engine before me? Should all the valves be dished? If so, what should I replace the flat valves with?