No weird noises yet, but would like to rebuild before it does have issues. It is at 160k miles.

 

It all depends on what you find and your abilities and available tools. Generally its not much different from any other engine, pretty straight forward.

Even with 160,000 miles and you have nothing weird going on, I would just leave it. The 3.8 is one of the most reliable engines GM ever made. As long as you change the oil semi-regular, you wont have problems.

My 96 3.8 has 281,000 miles on it and the deepest I have ever been into it was to change the intake gasket, valve cover gasket and the oil pan gasket (twice). I just run Mobil 1 oil and change it every 10,000 miles. Not even a hint of engine trouble yet and it still passes California smog (not burning oil).