30# is way over for even a 3.4, let alone a 3100.
It is, if it's not boosted. Boost (more air) requires more fuel to accommodate.
Larger injectors are required, but must be accounted for in the tune, to accommodate idling, and other situations that occur when boost is not present.
This is a whole different situation - and set of parameters - than the "rich/hunting idle with the 17# disk type injectors" situation.
This is why I don't normally mess with boosted engines. It's a whole 'nother learning curve. Fan's is going to be an... experience. :-/