For 1200s you'll want to upgrade the Distributor to at least a magnetic pickup and ignitor non points ignition. The #1 goal is to get rid of the unreliable and ever-wearing contact points. You can also easily use ignition boxes like the accel 300 or MSD 6AL or pretty much any other box with a little work. Some people modify the engine to use a crank position sensor for fuel injection. See main article:Electronic Ignition.
Secondly, for better performance, get the distributor recurved. See Spark Curve.