MSD ignition recomendation...

The MSD is a nice controller, and I like triggering them directly off a factory magnetic distributor. But your not going to get 20-horsepower worth of difference or anything of that sort--especially if your car is already running fine. It will smooth out the idle and the rest of the entire range--not by a huge margin, but it is noticeable. If you get a 6al (not a 6a), you will get a rev limiter function, which is nice to have. 440Dart1970 above is using one of the older analog units, and they work just fine and can be found used for around the $100 mark. You don't "need" the new digital model. I found an analog used one for my '67 Plymouth lately, and it was a nice upgrade over a Pertronix igniter. MSD's can drive nearly any coil (but not all), and they have a lot of neat add-ons.

But if your satisfied with the function of your car currently, then there is no urgent need. However, if you drive it hard to the point of floating the valves, you may want to look for any system or add-on that provides a rev-limiting function. I have a feeling you don't do that.