The pinging you are describing makes me wonder if the distributor intermidiate shaft is a tooth off....ie car hard to start....pinging under acceleration,bring engine to t.d.c. #1 cylinder and make sure the rotor is pointing to the electrode on the cap....not in between two cylindes on the cap,if it is in between two cylinders the intermidiate shaft needs to be turned a tooth and this should also help the surge under power...it will increase the engines vacume,surge under power usually means a vacume leak but I have seen this same problem with distributor off a tooth,low engine vacume causing vacume advance to act eratic,just check it ...hope this is helpful
