Mallory Unilite Distrib

any one ever deal with this style GM optical distrib?

I like them

if that optical module goes bad will it still through some spark, causeing a rough idle? Or none at all?

no opti, no coil trigger.

ok so if i getting decent spark at the coil, and all the wires are good, but if spark is intermitantly getting to the plugs what would that be, bad cap,rotor button?