Well is this what you guys were talknig about. http://store.cal-mustang.com/cm_able/webpage.cfm?&DID=7&WebPage_ID=5 Which one?
You will want the ignitor, but I don't know which P/N you need. Contact them with your engine info and they will get the correct one out to you. It just goes in the distributor and replaces the points and condensor.
Well i havent changed the oil or spark plugs yet, but do after it warmed up ill put in reverse then right when i take my foot off the gas it just dies, same with when i go in drive?
Until you rule out bad plugs or their gap, timing, points, wires and/or carb you wont know if the idle is to low, causing the stalling or plug wires are bad or what is really wrong. A good basic tune up is the first thing. The Pertronix unit could be part of that, but properly adjusting the points would be a better starting point then spending the bucks on upgrades.