3671587 Heads 2.05/1.60 on 318?

The valve is .015 bigger than a 2.02 on each side...since we are talking circles here. The valves across are 3.65, then margin between , say .025? and on each side .100-.? =3.875..
About .075 left of the 3.95 after subtracting.

The chamber is probably opened up to a 4 inch + bore size, so that is what it is.. but the valve fits.