I don't think 83 had oil injection yet. The box your talking about is the spark advance module . . . just disconnect it and throw it in the garbage. Screamandfly.com and
www.biggerhammer.net are the best places to get information on that motor.
Blue - your motor is the same . . . except I think 84 had oil injection (and maybe the smaller 5 pedal front) . . . the worm gear saps a little HP . . . otherwise it's the same motor. I got the chart off screamandfly.com . . . it's from landandsea's dyno tests.