58mm Throttle Body

One of the best upgrades to the stock 3.0L's intake is the 58mm Throttle Body.  The stock size is 46mm and somewhat restrictive at the high rpm range.  Most people use a 52mm TB which can be obtained from any V6 Caravan/Voyager from 87-89.  Forward Motion also sells new 52mm TB units.  The 58mm TB can be obtained from any Chrysler Town & Country from 96-up with the 3.8L engine.  Some people have tried using the Jeep 60mm TB's off of the 4.0L but It requires a lot of porting of the intake plenum opening.  The stock opening on the plenum is 52mm so you have to Port match it to the new TB. 

A 58mm Throttle Body will give you an average of 8-10hp depending on the application.  Gas mileage may drop by about 1mpg.

*pictured here is Mark Sutyak's 58mm Throttle Body