Maybe , not sure as I havent tried it myself so cant compare the 2.
Probably though it would be easier to identify a G13 pheno in the G13SK x SK.
The g13 needed selection as most were towards the skunk side ,only got a couple g13 dominant from 9 or 10 females.
Great weed and very potent!
Btw I remember shanti said that the skunk he used to cross the G13SK from Neville was from an old Skunk line. Judging from the f1 plants it sure didn't resemble much the 'Shit' which is basicaly more like a pure SK1.