Comparative sizings of human to pred head??

[Giles]

Looking at PredatrHuntr's P1 Bio comparison thread, the size of the bio's appear to be very large and to fit the hero mask for KPH?? and a sculpt of this size may look rather large on my 6' body. Has anybody made a head which is more in proportion with an average height person and would be able to give me some idea of measurements? I'm starting to have a little panic as I'm getting closer to finishing my sculpt (custom) and I'm worrying that it may be too small. I think I've given enough extra for latex shrinkage though some advice would be greatly appreciated. I can't face trashing my sculpt after 18 months!

Cheers

Ps I will be making my own bio to go with this head and will not be installing lifts in my shoes etc just rolling with it all in proportion.