Valve replacement 1938 SS 2.5


I’m installing new in and outlet valves at my 1938 SS 2.5 cylinder head.
The new valves are standard size, with a valve stem of 5/16"
To which size should I ream the valve stem guides, what’s recommended ?

Thanks, John

I think the stem size is 0.309" dia for exhaust and 0.310" for the inlet and the guide size is 5/16" i.e. 0.3125".


Hi Peter,
Thanks for the information, just the data I was looking for.
Thanks, John