hi bart,those bores look glazed,very shiny is not good,in a previous reply a button hone was mentioned,use a variable speed drill and spin it slow!!move it up and down the bore 6 or 7 times,you are trying to achive a cross hatch pattern of about 45 degrees,35 is better,dont over do it!!just get that mirror finish off!! ,use kerosine to lubricate the hone,wd40 contains silicone,and can leave a residue not welcome during breaking in!!these "sratches"hold oil to lubricate the piston and cylinder,that black area on the pistons,on the ring lands,flame has been going there,new pistons might also be the choice here,,its apart now,do it once /do it well,im sure your local engine rebuiling place will give you some free advice if you take the barrel and pistons to them,do you really need heavy duty head studs?the money could go toward maybe a rebore?