Rough Running

Hey guys, just a small question

I bought a 73 240z automatic a couple of weeks ago. Its in great condition and everything works fine except or two things.

1.) I was at the lights the other day. When I accelerated the engine nearly stalled and it took about 3 seconds before it ran properly. It then ran really rough for about another 6 seconds with the car surging occassionally and I heard the engine "pinging"

2.) On the highway at 100kmh the car tends to surge sometimes in a pulsing manner. The tacho doesn't show any noticeably rise or fall in rpm but you can feel it.

I've booked it in to see a mechanic next weeks but any ideas would be great.