Jennifer:
Keep in mind that you probably already have a duraspark ignition box. Its the silver box with wires going to the distributor that’s usually on the firewall. If you don’t have one then you can use an after market ignition box that will do the same thing. (Summitt has a store brand box that’s cheaper than others) Or go with the duraspark box only, or you can also add an after market box with the duraspark to get even better spark. That extra spark really helps starting and makes the engine run noticeably smoother.
Here’s a site that gives the diagram for running several combinations of spark upgrade.
http://home.cfl.rr.com/mustangsix/Engine/duraspark.htm
BTW, I use Royal Purple in the MG and my truck, including tranny and rearend. It’s good stuff. worth the extra money IMO. And don’t leave off the things Mark mentioned, all very important.
Ringo