The casting quality was not great and yes a cleanup will benefit performance. Just don't leave the inlets smooth, a rough surface improves turbulence and swirl.
Steve Hammond
Two 2.3 Viva's, one 2.3 Viva Estate, one 2.3 Magnum estate, half share in a 1.6 Viva auto, and no time (HC183)
Started to clean out the ports. I matched the new inlet and exhaust gaskets to the head and dressed the lip line of the ports to within 2mm. Removed the casting lumps from the ports and spot-faced the bolt holes as far as possible. Although it looks like it has black or brown marks in the pictures these are only reflections - it's all a dull grey really.
This rebuild is not going as fast as I would like !! With hidsight, working in my front garden, in the coldest March on record was not my cleverest decision..
However the decoke is done and the rebuild can wait until the end of this Ice-Age.