I go along with the majority on this car.
Just fit some value for money extractors, any brand as they all outperform the cast iron manifolds and just leave your current catback.
A high flow cat for your engine will make 1-2rwk at best and really only make more noise so not neccessary.
High ratio roller rockers are good and will help the V6 breath and rev a little better although sometimes on older engines upgraded springs are needed or you may get valve flutter at the top of the revs which will actually lose you hp.
Probably the best performance mod (not nccessarily value wise) is lower diff gears and if you stay around 3.46 you should retain reasonable if not the same fuel economy as now but get off the line a hell of a lot quicker.
Top end will suffer although how often can you use top end on the street and how often would a quicker off the make and through the gears be of more use.
As for LSD I have way more power than your V6 will ever have without forced induction and I would much rather drive my car fast in the wet with an LS diff than with a single wheeler.
