Re: Cylinder head thickness

["Greg Solow" <gregmogdoc@surfnetusa.com>]

The original thickness of all TR-3, 4, & 4A heads was 3.330" measured from
the valve cover gasket surface to the head gasket surface.
                                                                Regards,

Greg Solow

Ps. Most heads con be milled without problems .135" to .150". Milling over
.160" begins to get shakey as the flat area oposite the spark plug begins to
get thin enough to have dificulty sealing the head gasket without special
internal reinfocement in the head. With a reinforced head we have run
comjpression ratios of over 12.7: 1 with over .220" milled off.  BUT this is
not s goal that I recomend.