Distributor shaft gear came off

Anyone ever had this happened to them? My 88 hatch has e303 cam and a 306 engine. The distributor might be stock is this ok? Will a MSD 5.0 V8 manual work or is there a specail one i need? I had the shaft gear fixed but I think it's on its way out again, im getting an eratic idle and some backfiring, this happened last time just before it failed.

So someone mentioned that i need steel gears. Correct? I don't want to chew up the cam gears. What about the bronze gears or murry's speed and custom sell a Carbon Ultra-Poly Composite gear. Anyone?

How hard is the swithing of gears? just pop the old and put in the new? Or is there more to it?