the .01 doesn't really matter, it is just who you get them from that will vary... some have 4.10's, others 4.09's.... The gears will really make the car fun... I have wanted to do them for a while, I just can't justify the cost right now... There is quite a bit of work involved... I would strongly suggest you have someone that knows gears do the job... A friend of mine had it done, and the guy didn't set them up right.... he cracked a tooth and wound up going back to stock gears... He wound up paying to buy the gears, put them in, then put the factory gears back in... go to a good gear shop that will stand behind their work... Some of the things involved include taking off some of the rear suspension components... you need a good lift, and a bunch of time....
If you really wan to wake up that LT4, go with Nitros... you don't seem especially worried about how long the engine lasts, and nitros is a super cheap mod for the power gains... that and the price tag should be less than gears if you do the nitros yourself