No the 1999 and 2002 1500's are different body styles.
Not with out major electrical modifications. The 2006 has different connecters, and receives power from a different computer.
On the radiator...
yes you can
The radiator plug for a 2006 Dodge Ram 1500 is located on the bottom of the radiator on the right side. It is used to drain the coolant during flushes and fluid changes.
It is on the lower driver side of the radiator.
18.7 liters in a radiator flush and fill in a 2004 Dodge Ram 1500.
Radiator. Remove the cap and add coolant there.
1994-1997
It doesn't have one.
The drain should be on the lower drivers side of the radiator.
There where no factory installed grease zerks.There where no factory installed grease zerks.
The biggest factory installed engine in a 1998 Ram 1500 was a 5.9L V8.