Searching for Valves, I found a source for cheap Stovebolt parts:
http://www.rockauto.com

grin

They sell a 1956 Sealed Power exhaust Valve for $4.12
instead of the usual $14,-
valve guides for $1,42

last week I bought a clutch set for $80, and water pump for $24 ($4 core)

They carry parts from 1949 trucks `n cars till today.

Frank