It probably can be done in the car, but I would bet they did it when the engine was out. Either way, it really isn't necessary at all unless you are really serious about racing. Also, high oil pressure can be hard on an engine when its not needed, if you're just crusing down the road with 70-80psi oil pressure, thats not good. Its not something that is going to benefit you with your 13 second daily driver IMO. An extra 30psi oil pressure is a lot. Just my opinion though...
I agree that it is much easier to do it with the engine removed....I just want some feedback from someone who did it with the engine in place.....Scott??
Although it is probably not absolutely necessary, I don't agree that it can do any harm, except maybe a little risk with leaks past seals...but I have low miles and the engine is still fresh. The OR rods should help keep most of the extra volume down in the main journal bearings and help to quicken oil flow on start-up. The extra pressure should also help now with the additional power I am making to keep the journal bearing oil film a little larger which should lessen the chance of particles scoring the bearing surfaces.
They recommend switch to a lighter grade of oil, the 2004 recommendation of 5W30 instead of the 10W30 that is standard for the 2000'*.
I would like some other opinions before I install it.