The reason why everyone is using a non-standard REQ_FUEL value is because that's what MRSLICK had in the MSQ files that he posted.

I use MegaTune calculated REQ_FUEL values in all my installations. This way, when you install a different set of injectors, all you have to due is adjust your REQ_FUEL and enrichment settings. If you use a non-standard REQ_FUEL value, then you have to guess.