Hey everyone!

I'm new to this forum and im new to the motor swap game. Recently started having some motor trouble with my 02 Tahoe LT. I got quoted about $3,300 at the dealership but even my mechanic said he would advise that i not spend that kind of money on a motor with 171K so i set off on a mission to solve a problem and decided to look into swapping the motor. The body on the truck is clean so i want to keep it around. I don't know much about motors, eletronics i can talk all day. Anyone have any info on what type of motor i should be looking for, should i even go up from the 5.3 to a 6.0? Just looking to keep Good ol Tiana rollin on the road! Any wisedom you have would be greatly appreciated! I also keep hearing about LQ9 and LQ4 motors but i'm not familiar with them at all. Thanks in advance!