i have always had good luck with 10 initial, and 36 total, all in by 3000 rpm. you can try as much as 14 initial but be ready to back off if you hear the motor detonating.
I told him that he should check his timing with a light, make sure the outer ring on the balancer didnt slip causing inaccurate timing by finding TDC. I was running an old balancer, and my timing was 25 degrees initial with NO detonation, just decreased performance. I put on a new balaner and found out that the outer ring slipped, and I re-timed it to 10btdc.
I also told him he should take his dizzy apart because its pretty simple, check the mechanical advance springs and see which advance arm it is on. On my dizzy the advance plates were gummed up and sticking, so that helped out a lot.
I also checked the vacuum advance unit for functionality, and installed a pertronix Flamethrower II pickup kit and coil, which I hightly recommend to everyone still using points, but doesnt want a full MSD ignition system.
I also suggested using a vacuum gauge to help set idle mixture settings on the holley 4160 style carb, and to verify the float levels and overall engine health.
Come on... taking apart and cleaning a distributor is fun!
Also of note, whoever put my dizzy together mixed up the 2 springs for the mechanical advance... one was too tight, the other was so loose it actually fell out.