For reasons unknown, the S3 head image would not isert when editing. This is the image referenced in the above post. Note that the modern head has less squish band area, and a wider shaped bowl area of the combustion chamber. If needed, this style head could easily handle a squish clearance in the 1mm to 1.5 mm range with ease, possibly even as tight as .5mm. The critical key being keen to not increase compression excessively.