I have a mallory unilite and promaster coil setup, what is the difference between that and an HEI on a '67 396 with a slightly hotter than stock set up? :confused:

With a GM HEI you can walk into any automotive store and get what you need. Break down in the middle of nowhere with some of these other units and you may just be there for a while. The HEI gives enough spark for street engines.

The HEI is an inductive storage, current limiting ignition that will produce more energy and more voltage than points.
A Unilite is simply an electronic set of points. You don't have to worry about pitting, point bounce, point wear etc, but the spark energy is not much different than points (assuming the point system is in good condition).
If you add a Hyfire box to the Unilite, then you will have something that will exceed the HEI, especially at high rpm. (assuming a stock HEI).

RobbMc, Mallory Engineering department.

Hey Robb...How much does a Blaster2 coil improve the ignition over stock with points? I'm running the unilite dist. w/o vacuum advance and the Blaster2. I've been thinking about a Hy-Fire box,just havent done it yet. I don't think there is any e.t. in it at my performance level,she don't miss a lick.

thanks robbMc- plan simple explanation! :D Would I notice a big diff w/ the Hyfire over the promaster?

If you aren't running over 6500 rpm and you don't run over 11 to 1 compression and you don't use nitrous or a blower, a simply distributor with electronic points (Unilite/MBI/Pertronix etc) and the right coil can work just fine. However, sometimes it is nice to run a box anyway just so you can have some of the bells and whistles such as rev limiters, retards, etc.
70conv; If what you have is working well, I doubt that adding a box will make much difference.

Thanks again RobbMc! preciate the help-Dave :D