I'd start with a basic tuneup if it has not been done in awhile. Then I'd clean the fuel injectors.
3500
I don't understand the question
K1500 is 6-139.7mm/6-5.5"
It is screewed in the engine block over by the starter.
posable Catalytic Converters pluged
ON the rear bottom/side of the oil pan(under the truck), don't confuse it with the transmission drain if auto.
133 foot lbs. hub to knuckle, 177 fot lbs. axle nut
Could be 10" drumsor if it has heavy duty brakes it could have 11 1/32" drums.
If 8th digit in VIN is the same, then yes
ive seen a set of 285/75R16s on a similar year but it looked awful close to rubbing the fender and bumper
NO.
the engine computer is located behind the glove box. remove the glove box door and inside. you will see it on top of the H-VAC