You can buy a ready to run distributor that needs nothing else to run (although an improved coil and wires are recommended)Other distributors will need a module to control the coil. So it depends if you are talking about MSD pro billet "ready to run" or not. Either one, or an under the cap electronic ignition conversion will improve idle and make starting a little easier.
However even when my points were a mess my engine always started easily. I think something else must be a little out of tune.
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'68 coupe 289 C code
66 heads, edel 600cfm carb, performer intake, dual exhaust http://www.geocities.com/ottouk_77/68mustang.htm