TBI Fuel Injection on a Slant 6

a properly tuned and maintained carbed slant six should be almost dead-nuts reliable. an MSD module might help but if everything is set to the way it came from the factory it should be very dependable, i mean, they wouldn't have made millions of these motors if they had chronic reliability issues.
don't know what shape your car is in, but if its pretty original then i would suggest re-wiring if you feel you are comfortable tackling that type of project. i recently re-wired my 65 Chevy Van, it took about 6 evenings and a couple weekend days but it wasn't too hard. also i did it in the driveway. anyway, this is the BEST upgrade i have done to the car in terms of making it "turnkey", everything works good now, bright lights, plenty of juice for accesories and it runs better. this is on a moderately built straight-six cyl, with dual carbs, dual exhaust, msd, etc. This motor has been dead-on dependable for almost 5 years now, about 40,000 on it and it starts up with the first turn of the key every time, even in sub-zero winter temps.

anway, what i'm saying is that instead of throwing money at fuel injection, why not also try to improve your driveability and reliability by looking at other areas of the car, which in the long run you will probably want to address at some time anyway.

are you currently having problems with the car? if so, of what nature? is it built, modified, or stock?

-tim