138.7 is a huge difference to 139.0mm though!!does not sound alot but it is in terms of long term investment in an engine/head.

as for 137.0mm,that really is scrap area,your well into the valve seats at that but with money and skill its ok for a N/A aplication,but at 137.0mm you have lost your squish area for combustion.

matt,you really hate traders dont you!!your always having a go at them,i would think pauls forgot more about cosworths than most folk claim to know in this land!!

i guess over the last 3 years ive maybe had 50 cylinder heads,thats a concervative figure,of which maybe two were at 139mm,one i distinctly remember was at 139.1 and i got £700 for it to a guy in finland.

as for you waiting for cosworth to recast heads,it will never ever happen,if in your wildest dreams it did do you know how much a knew one would cost?