If it's a 2011+ GM car still under warranty, then get the Gold because it's licensed.
If it's a pre-11 Cadillac or Corvette, then get the ST syn, which claims 4718M.
What kind of car is it going in?
But there's a better choice, if you have a Napa nearby: Napa's house brand Synthetic, which is Synpower and now officially licensed dexos. Plus, you get individual quart bottles which are easier to pour and no quart or half-quart left over in the big jug!