I have a C6 four-wheel drive with a 205 transfer married how hard is it to use a C6 automatic

 

Welcome to FTE.

Looks like you saw a squirrel or something. "....how hard is it to use a C6 automatic...."

Possible answers:

--put it in drive, go.

--if it's a 2wd trans for your 4x4, take it all apart, change the rear housing and output shaft

So, let us know what you're driving at.