Timing Chains - addendum to: JU Question - Spark Plugs?

[kranky_kel]

You may remember a recent thread of mine: JU Question - Spark Plugs?

Well, after taking the Jeep into the mechanic I have a completely new look at my jeep probs. The mechanic found that after clicking over the 100,000-mile mark, all my sensors and injectors are in perfect condition (knock on wood). He said that everything is working the way it should, minus the timing chain and catalytic converter. The cat is gone (I knew that) and the timing chain has 8 degrees of slack in it. He said that beyond 6 is out spec and 10-12 you start getting nervous of causing damage.

The mechanic (a friend in Idaho 4x4) told me that he would like to throw in a roller-gear timing set and clock one of the sprockets 4 degrees to give the engine more torque.

A) Does the roller-gear timing set exist for a '94 4.0? I can't find one.

B) Does clocking the sprocket give more torque without effecting gas mileage? (I know, weenie question)

C) Is swapping out a timing chain something a practicing shad-tree mechanic handle (read: no special tools)?

Finally, I would still appreciate opinions on spark plugs. I do need to replace mine soon. I am leaning towards the Champion Truck plugs, I have been heard a lot of good things about them.