this is form one newb to another but its basic car stuff...
seems you are having some electrical issues, to say the least.
reverse lights: make sure all of the sensors are connected on your trans, check fuses, bulbs.
lights surging: what's happening during the surge? does it change with RPM? check the lighting thread, i've seen some people asking about dimming lights. sorry its the exterior apperance section here http://www.ls1tech.com/forums/appearance-detailing-18/
backfiring: check timing with a light. does it run rough? check spark plugs to see if you have injector/ignition problems. could have something to do with that crane tuner also...
just a bonus, could you post a pic of your intake? i'd like to see this greddy/K&N lol
black 98 Z28
rebuilt LS1 with cam, valve springs, LS7 lifters, bbk manifold, clear lid, magnaflow y-back, LS2 chain, T-56 with MGW shifter.
strano springs, sways, koni shocks, UMI phb, offset upper arm bushings, 1le rear lower bushings.
17x9.5 chrome SS 10 spokes on 275's all around
(pic coming soon...)