Intake Manifold Recommendation
http://dodgeram.org/tech/gas/specs/5_9v8.htm
If you have never heard of Ginos Garage, they are well versed in the Dodge Magnum engines. This is from their experience.
I checked with a machinist friend that said Chrysler dropped the 1.88 intake valve in 2001 in favor of the 1.92" through 2003 when they discontinued the magnum. The only 5.9 magnums that came from the factory(according to rock n roll books and Chrysler "experts" were the 5.9 RT and the 5.9 that was installed in the 1998 Grand Cherokee Limited. The only 5.9's produced in 2001-2003 were Rams, Durangos Dakotas (not to many, mostly 2wd).