I have a MSD Blaster coil on my car and i noticed that it moves a little in the bracket....is this coil supposed to be grounded directly through the coil - bracket or through the wiring?

 

I would suppose the wiring. Mine also moves a little in its bracket.

 

the yellow Accel coil is better and doesn't move

 

couldn't tell ya about the loose issue (in 96-97 designs, you need to drill out 2 rivets on the mounting bracket and tehn bolt the new coil in place... if it's loose just tighten it)... I dont' have a 93.

I just ditched my new MSD coil though for the GM unit... finally revs clean to 7000... no issues like the high rpm miss I was getting with the MSD.

On a stock or bolt-on engine I doubt there's any difference between the MSD and GM unit... at high compression or boost I'd be wary of using the MSD.

No experience with the Accell unit yet.