When I got my cam done up at colt cams, which is actaully a few blocks down the road from me, he was adimant that I ran zink additive to give the cam an additional final critical barier during break in, and he stongly suggested running it always to preserve the cam. He said that newer oils have cut additives alot and he is seeing flat lifter cams wear out across the board. Rollers are doing alright though. I run zink and moly additives with full synthetic 15-40 amsoil/ redline. During the cam and engine break in I only ran the zink with dino oil. I delayed adding synthetic oils and moly for 10K to let the rings get a good chance to seat. If you run a turbo hard you should run full synthetic, in my opinion, as the bearings in a turbocharger are a tiny crucible that will destroy your oil one drop at a time.
