A couple thing's to know and look for when tearing down your 4L80E
Park Pawl Plug for dual feeding, https://amzn.to/2V32f7D
Transmission fixture for benchtop, https://www.ebay.com/itm/Transmission-Holding-Fixture-W-BASE-T-0156-B/264040374911?hash=item3d7a08627f:g:SdQAAOSw7NNUEhtK:rk:1:pf:0
Link to me on Patreon if you'd like to support the channel, https://www.patreon.com/thedrivewayengineer