lots of questions.. need lots of answers!!!
 

i have a 99 silverado 1500 z71 5.3 v8. i already have descreened M.A.F, C.A.I, tb spacer, flowmaster super 40, and superchips flashpaq programmer.
1- like every body id like more torque, power, and acceleration. any and all ideas would be a huge help.

2- my 4 wheel drive DEFINITELY doesn't work. first noticed it a week after i put in a new front left CV axle. if i press the 4 wheel drive button the service 4 wheel drive indicator pops up. when it first stopped working i could still hear it trying to engage but now it doesn't even try. and i can hear some clunking coming from under the front end. i haven't looked to see if the front axel spins yet( planed on doing that tomorrow). i got a feeling its the transfer case but im praying its not. could it be anything else?

3- one thing iv been wanting to do is put a 4:10 gear in it. a friend told me to get a new or used one for a 2500 cause it would be more durable for towing and burning tires. lol will a 2500 4:10 gear work in a 1500? and would i need to modify anything to make it work?

4- this one is my biggest concern! when i put the pedal to the floor i noticed that as it begins to accelerate it will sometimes lose power to the rear wheels. the engine is still revving up but the truck accelerates slower, sometimes not at all and when the rpms get up and it shifts it will shift REALLY hard.i think it only does it in 2nd gear, and it does it more frequently if the truck hasn't warmed up yet. the trans only has 35k on it and the rear diff only has 15k. what the hell could it be? this is way out of my league lol

im not very mechanically inclined and i really need help with all this so any info would be a huge help! thanks in advance