flathead valve replacement question???

if i replace my early 39 valve ***emblies with later 49 style do i have to have the valves and the seats cut.motor was rebuilt and i'm replacing the cam and lifters,but not really looking to rip the whole thing apart.just thought i might upgrade while i'm in there.

 

Unless you have adjustable lifters you have to have the valves (done) to set the valve clearance.

 

If it were mine I'd install a few and lap them in to see what the contact is. If the new valves are the same size and profile you may be OK with the seats as is.

 

i will be running adjustable lifters.does that mean no machining?

 

No grinding the stems for clearance but you still need to lightly lap the valves in to confirm good seating.

 

I agree, at least hand lap the valves. You can grind the seats with the engine block in the car, too, no further dis***embly required than to change the valves. Just a PITA to clean up after.

 

thanks guys.-ray