1968 chevy c20 3/4 ton custom camper 4l80 trans swap

[Jbuky]

so im having some shift issues. Im using the tci ez tcu on my 4l80 e trans. got all the settings correct or for the sake of argument lets say i set it up perfect for my aplication. however i think i am only getting first and second gear after that it says its shifting but it performs like the tcc (torque converter) has locked. What could cause that? The internet said the 4l80 takes 3.5 gallons but it drank more like 4 gallons of cam2 tranny fluid. Is it over filled? aftermarket dipstick says not. My motor is a 350 gm crate motor. edlebrock intake and carburator. bla bla bla it lined up with my 4l80 using 3 existing holes. we drilled and tapped 2 more. it fits. we only needed to remove 2 inches from the drive shaft and then buy a 4l80 trans yoke th400 yoke fit inside but outside gauge is smaller. you need a 4l80 yoke. moved the the tranny mount acourdingly, i dont know what my rear end ratio is. we just swapped drum for disk in the frond only and it needs alignment. bad. but for the most part the swap was a totall success but truck is running 35000 rpm at 60 mph and feals like it wants to shift but it says it allreadty has on the tcu live readout screen. im supposed to go from a three speed to a 4 speed with overdrive. wtf i was thinking id be cruising down the freeway at 75 busting 22000 rpm or lower. whats a good place to start looking for a solution please help im desperate.