Oldsmobile/Buick Repair: Oldsmobile engine pinging, oldsmobile delta 88, spark plug wires

Question
Hello,
 I have a '66 Oldsmobile Delta 88, 425ci/300hp engine, 2-barrel.  Before I had some work done on the car there was no pinging.  I had the single exhaust pipe replaced, from a 2-1/4" to 2-1/2" with new muffler.  Then I brought the Olds to get the timing corrected, as recommended by a diagnostic center.  The mechanic said he adjusted the timing from zero top dead center, to 8 degrees before top dead center.  Now the engine on a steep hill will start to ping lightly.  The mechanic claims it's the regular grade gas (which is recommended in the owners manual).  Is the timing too far advanced, or is it something else?  I'm replacing the spark plug wires as recommended from a mechanic a year ago.  This was my fathers car and I'm restoring it to a tuned car.  Thanks.

Answer
hi finn.well it is hard to set these old engs to factory specs since things are worn they won,t meet factory specs.timeing chains valves .all these parts wear.possibly the advance in your distributor is not working right.when you push on the gas the timeing has to fully advance to give you the power you need to burn all the gas.here is what you will probably have too dois tweek the timeing a little.your mech set the timeing as you ask him. drive the car get it to operateing temp loosen the distributor enough to move it move it one way or the other drive the car if this is better but not quite right move it again same direction.now if it is worse go back where you started and go a very little the other way .if none of this works  new distributor will solve prob..please take a moment of your time to rate my help ty billymac