4l60 to 4l80. What am I forgetting
 

As best I can tell doing my research on my phone with crappy service, I'm gonna need (to)

4l80e
converter
modify my transmission crossmember
shorten driveshaft
add 2 wires for ISS
modify grey transmission connector wiring.

This can't be it. What am I leaving out, forgetting, overlooking etc?

What all needs to be changed in the tune, and will my 4l60 flexplate work??

I don't know about grey connector, you can add the wires at the computer plug.
you need the 80 flexplate and yes def have to change tune.

swap the whole tranny segment in the tune, not shorten the diveshaft, but change the yoke and shorten it. Add the 2cd vss sensor to the pcm.
If you order a hybrid converter you can keep your flexplate,

looks like you got about everything.

you have to extend one of the trans lines.. i used some brake tubing and a compression fittings... yes you have to swap two pins in that plug.. i bought a kit from speartech.... but it is real easy to move the 2 pins.... this guy usually has some transmissions... its where i got mine... his name is sam and he is in pierre part... his number is 985-414-0892.. get the yoke/ dipstick tube/ flexplate and shifter bracket when you get the trans....

You can get a oem trans line from a 2500 suburban it bolts right in. Mine was $30 from the dealership. It could probably be had to next to nothing from a junkyard.

I know this might be a given in your house Matt but I see one thing missing. :chug::nod: Looks like you have the rest pretty much covered! Good luck with the install. Vince