If pissballing around with fuelling on the standard GM map, the trims need to be more or less 0%, as they soon get grumpy if they drift off dramatically.
This is something that a lot of the crap you read on of the internet that shows most people don't know their arse from their elbow. Higher flow injectors, higher pressure FPRs and so on do not help in the slightest if the originals are good enough, all that happens is the ECU has to battle harder to keep everything working right, and every time you clear any codes, the thing will run like a sack of shite.
If you can get more air in (and out - theres another issue though), then increasing fuel flow makes sense, but only if you can keep the trims, long term, around the 0% mark. Try to understand what is going on and why, rather than believe what the bloke down the pub's dogs mums brother says (or what you read on the Internet in this new fangled online world)
Hope that makes sense