I hear a pinging noise from the motor on the driver side.only happens when i gun the gas,i changed the gas to 83 octane no change.doesn't happen when normal driving.i have a 455 motor in the car i think the timing is a little advance.the pistons are 20 over and a little cam work as per last owner.what should the timing be at thanks.

 

If you have a different cam than stock, you can't use the factory timming. Aftermarket performance cam will need more timming than a stock cam. Advance it as much as you can without pinging.

 

Go to a higher octane rating. The minimum around here is 87 then 89 and then 93. That could be the problem right there.

 

add some octane boost, if it is a daily driver then just reduce the timing a degree or two