i just rebuilt a vspec for a local , he provided parts which i am pretty sure were arrow parts and all fit perfect , ran great

parts quality/finish nowhere near that of the japanese made vspec parts but crank seemed to be much harder steel (bonus) , needless to say the engine ran great

the piston looked "speckled" as you said marcus , maybe neal knows for sure but i am pretty sure the partsare a direct fit to the original OS engines bore x stroke combo

btw , the rod didnt look near as finished and in past experiences rods with sharp edged machining did not last

hope this helps

if your curious novarossi machined piston is quite a bit heavier than cast