I have a 2000 f body with a TH400,pro yank 3800 10.5 billet stall & a cheetah scs reverse manual shifter in my car and I want to convert it to a built 4l60E. The car was originally a 6 speed. Any other things you guys can think of that i may need that i dont have listed below or any sugestions. I plan on selling my current setup.

built 4l60e
circle d stall
tci controller
crosmember
driveshaft
stock shifter
new console cover

 

Looks like you have it all covered.

 

Can I use the same flex plate with the 4l60e? I think i have a tci #399753 that i am curently using with the th400.

 

That is the exact Flexplate I have on my LS2 with 4L60E.
Personally I would skip the TCI controller and add the 4L60E wiring to the harness, but I am very comfortable with wiring. This would also require getting the 4L60E-segment software installed in the PCM.