At the very least put the heavy snap ring in.
Leave the pump spring out. Those are for raising line pressure without a tuner.
The little piston/plug deal with the hole drilled through it, it prevents pressure spikes in reverse.
4x4s can avoid pressure spikes by backing up heavy loads in 4-low.
2wd truck obviously cant do that.
I put the snap ring, relief piston in my trans when building it.
No problems so far.
Tip: the pump has to be separated to install the relief piston. When resembling the pump make sure the two halves are lined up to one another, think 2 quarters stacked.
Or the pump will not want to bottom out when ya go to put it in.
On edit: im running Matts tunes as well.
My trans has
RCD converter
Elite comp gpz clutches
Everything billet
New pump
New ford solenoids
Trans go reverse kit
No hunting for gears, super smooth shifts.......just awesome.
Arguably the best things that were done to my truck : gearhead tunes + built trans.