The valves are whatever brand came stock in the merlin heads at the time they were produced? I took the tore up head to my machine shop today to see if the head could be fixed and they said it would be cheaper to buy another casting then fix that one : ( and also I asked about the valves in the heads and they said that they've seen the merlin heads especially break allot of valves due to the fact that they use the cheapest valves they can get there hands on the time the heads are assemblied.
Ed I tried to convince the car owner when I started driving the car to raise the shift point merely for the fact that the cam made more power higher up in the rpm range we were just starting to make power when it shifted but he insisted on leaving it at 6800 cause he said it was easier on the "motor", after what you stated earlier I guess he was dead wrong.
Thx all for the info I will take head and shift my motor in "MY" car at 1000rpm under peak horsepower and shift into peak torque rpm, which would be right around 7500 rpm. Charles