A few things I think one could look at for choice of plugs is what was used in the vehicle the 7730 came from, and what was used in the engine in the car. Lots of people have said that the stock Fiero ECM doesn't like plugs that weren't installed from the factory. Brand, heat range, etc.
For instance, my 7730 came from a 3.1 Beretta. The engine from a 94 Camaro. I'm still running the stock 87 ECM with the distributor, so I'm running the plugs recommended for a 2.8.