I have built a 350 bored .040 with a high flow intake TPI intake, moderate cam, 10.25:1 compression, Different cranks/rods/pistons, AFR heads, and some other small performance modifications. I set the timing at 6 degress BTDC per factory spec. However, there is almost nothing factory about my engine anymore. Should my base timing be different than factory spec? What brought up my question was a Horsepower TV episode and recommendation by a mechanic. Now granted, I do not think Horsepower TV is the trusted source for car advice nor is every mechanic. However, on Horsepower TV they advanced timing past factory set point and gained 22 HP. The mechanic told me to advance timing until you get detonation and then twist distributor back just enough to stop it. Is there any truth to either of these methods?