Base Timing

I know I know, total newb question thats been asked a million times. I should know better ANYWAY! Im in the middle of a long distance move so I dumped the stang off at my buddies place (he has a 91 notch). I told him to drive it once a week to keep it fresh. The first week he gave me a call and mentioned it had a lot less power then when I first got it (which I knew) and he was concerned with the 5-6 times you had to turn it over before it would idle (when cold). He asked what I had my timing set to and I told him 15-16deg base. He freaks out and says that should be my total timing, not my base and I was running way to much timing. It was my understanding that our cars were set to 10deg base from the factory (20 total) and depending on mods and fuel you can safely run 15-16 base without detionation. He says that your base should be set to 5-6deg initial and 15-16 total (after you plug in the spout). Whos right?