I believe I found the original tune that was on the computer that I believe to be the stock 2000 Silverado computer. It was OS 09381344. In table B4001 it shows the injector flow rate at 3.1250.

In the current OS on that same computer it shows the same flow rate table as 3.1797.

So should I change the flow rate in my 12212156 OS to match 3.1250 instead of 3.1797?