Take an intake gasket (the "turkey pan") and some spray on gasket sealer or machinist's blue dye and spray it against a piece of cardboard. Or better yet, just bolt the gasket to the head and spray with the blue dye. Once you remove the gasket, it will leave a perfectly marked area to port out.
I was thinking exactly the same! Unfortunately i dont have a gasket at hand, So that's why i wanted to have a drawing.. I could have let my brother 3D print a template.
5one9, Nice porting! i'd like to do the same, But need to find a way to put them in the right location and not get the front one slightly higher of lower than the rear. It would be a shame to order just a set of gasket and have them shipped alone with the high shipping costs to the netherlands..