I Just purchased a 97 gmc suburban that i am going to use for hunting.
It is getting a 6in lift with 35s. I am planning on switch out the 3.42 for 3.73
(maybe 4.10's) and I would like to put selectable lockers in the front and rear
but all i can find is one for the 3/4 ton IFS. Anybody help with info. on this

 

First I would go with 4.56 gears and nothing less with 35" tires. Not sure about your transfer case but I've been informed that a locker or any other diff. can not be installed.