Last time I tuned an LT4 was in... umm... 2001 or 2002? Step 1 was to remove Hypertech tuning. After that I worked on reducing delivered fuel at WOT. That helped improve power level but I had a chassis dyno available so I could make changes in increments. The next step would have been looking at the WOT enable parameters to see if they seemed appropriate for the owner's style of driving. I seem to remember that I liked much of the LT4 tune as was and without having time to do some on-street driving I wasn't going to make too many changes.