4 barrel LA Intake

I don't understand it. Plain and simple. I grew up with carburetors, Waylon Jennings and bonanza. Lol this is coming from a 25yo. Temp switch has been replaced. O2 sensors have been replaced, vacuum lines replaced, injectors spray good, full tune up done (including filters),

No check engine codes

put a carburator on it then, done deal; you won't see much gain, your truck is made for heavy duty work and a granny 4 speed isn't made for milage, neither are 4:11 gears