Well, i've had 2 Mallory Unilites, one being a Comp 9000. They're awesome until the module goes out and costs you $90 to replace it. You could go with a Pertronics electric module swap on the stock distributor and have a very nice setup for a mere $50 or so.
What are the mods on the '85? Is it stock? Do you race it? Could you benefit from full mechanical advance or should you stay with vacuum? There's lots of variables.
Right now its a 306, AFR headed, 650dp holley, e-303 cammed. I plan on hitting the track soon. Once i get it running right. You have a link for any dizzys, thanks SSP.
The Mallory that i use is no longer in production so i don't have any links. I'd check out Summit and just type in your year vehicle and browse through. A lot of people have told me Mallory's suck but i've had good luck with mine even though the module just recently burned out on me. If you run it stand alone then you will eventually need to replace the module...it's one of those things that's just gonna happen. But, if you run an MSD box or Mallory's box with it, they'll pretty much last forever because you bypass the module altogether.
Personally i liked mechanical advance in mine. Most will tell you that on the street vacuum advance that has been curved properly for your setup will be faster...and that's probably so, but my experience is a little limited and what i know is that my car has always been faster with the mechanical. Right now i'm on a really odd ignition setup....stock Duraspark II distributor with a GM HEI ignition module for the ignition. These modules are nice in that they put out nearly as much spark as an MSD box (minus the rev limitor) and they're only $17 from the parts stores. I'm eventually gonna try to recurve the distrubutor and see if that makes any difference.