I am just curious , I have a 91 na and I was thinking about installing msd 6a , is that worth it ? What kind of advantage will I gain if any ? Also can I run that on stock coils or do I have to upgrade those as well ? I would like to eventually anyway but I mean for the time being

 

nobody?

 

One box will power the leading coils setup only.
you will need a box apiece for each of the trailing plugs.
You can set up the 6A to run in and out of the leading coil only(and not have to get 2 more boxes for the trailing).
advantage?.Some say hotter spark and about 10 miles per tank(max).
The box will pay for itself in a year,if you bought it cheap..lol!

 

The long and short of it is that it's not worth the trouble and expense. The only time these boxes are helpful on an 2nd gen is running high boost on turbo engines or using aux injection. The stock 2nd gen ignition system is already quite strong and reliable, not a typical weak OEM system of the era.