Silly I know

or you just go into any place that sells stock replacement parts and ask for a cap and rotor for a oldstyle GM distributor (the stuff vith points before the HEI was invented) works great as long as you use Heavy duty replacement parts.... only problem with doing so is that you will also need to change your cables to standard terminals since the HEI style cables dont fit the older type of cap.....
those cheap caps and rotors will last about one summer of daily driving with a MSD ignition box, while the MSD Cap and rotor will last maximum two summers of dailydriving