timing retard

Posted this in supercharger tech with no replies. Thought I would try in here, thanks guys.

Guys I am looking for some info on a timing retard box such as the btm included with superchargers. I have a '91 mustang, plan on supercharging this summer and am trying to get the items need such as injectors, pump and maf now.

Question is do I need a boost retard if I get a custom tune. First thing Im going to do after I install the charger is get a tune.

Secondly, is there a ignition system that has a retard built into it. My msd took a crap so I ws hoping to kill 2 birds with 1 stone.

Thanks

Thanks Mill house. i am going to pick up a 6al then I think from this poinnt, and get a tune as soon as the s/c is bolted up. Actually I found a kit I might be buying now.