4L80E HD2 Shift Kit and Circle D Torque Converter Install 

Pouring fluid from a fresh gallon rotate the container so its parallel to the ground rather than perpendicular and it will pour better when trying to to be careful. Nice video documentation thanks.

I did the EXACT thing with the EXACT same converter. The only difference is that I did not use the Sonnax valve (And did not drill either). Trans functions well but there is a hydraulic buzz that is loud in reverse, and slightly noticeable in other gears. Gets louder when the trans is warmed up. Sounds like pump "whine" or "Grind" like a skid steer with the throttle too low. The core was a running and driving unit. Pressures are about 175 in neutral, 125-130 in gear, 250+ in reverse, and crazy when you kill the engine for a brief second. I am going to stuff the Sonnax valve up there, as well as the sonnax sleeve with the O rings and see if that helps. I was also concerned about high pressures in the torque converter pushing on the thrust bearings, but maybe that is unfounded. I don't think I can get the balance plug out without pulling the trans. Interested to see if you experience similar hydraulic sounds, or if you have any thoughts?

If trans is apart do the dual feed mods. The HD2 kit kinda backdoors this mod through the valvebody but not as well since your not taking the trans apart to do correctly