Is my 340 Overcarbed? Avg 5-6 MPG

Id say u need more timing
But mostly all aftermarket carbs come out the box all fucked up
U gotta bring it to a good carb guy so he can tweek it
My quick fuel runs in low 12s on the wideband when cruzin too
Watch, if u jus run primarys goin up a hill, it will run way lean 15-16+
Then wot is usually good around 12s

But carbs need to be tweeked jus how we do our motors
Im about to do my carb after im done with my 4speed swap

Find a good carb guy, cuz im pretty sure the meatering blocks gotta get all reworked