RD4 Cylinder Head Valve Recession ??

I own a RD4 and I'm having the head overhauled with new valves,guides and inserts.
The fellow who is doing the work on the head asked me what the valve recession is. I think this means how much above or below the the head the valves should be.
My question is, if this is the correct assumtion, does anyone know the correct amount of recession, plus or minus ??
Ken Wise

Use the D4400 info:

This should make him happy!!
Thank you ;
Ken Wise