Hello, I just purchased a 2004 Ram 3500 Dually from a used car lot, only had 98 miles on it when I drove it off the lot. The door sticker says it was built in April 04, I guess it was a fleet vehicle that didn't get used. How do I find out if it is a 600 4.5 model?

It will say the hp rating on the side of the valve cover if it is 325 it is the 600

There is a sticker that says model IS6 325, as well as a bunch of other information. Is that it?

After January they are 600's

yes, you are a proud owner of a 325/600 truck. You should also qualify for the TSB 18-037-04 flash. I suggest you go get it. I helped my gas mileage 3 mpg. I took a 150 mile (one way) trip 4 months ago at 70 and averaged 18.0 mpg (cruise control) on the highway in my 04.5 2500 4x4 CTD 600. Had the flash about 3 weeks ago. The very next day after the flash I took the same 150 mile trip and averaged 21.59 mpg going 70mph (cruise control).


If you are experiencing less than 17 mpg fuel economy, go get the flash!!!

17 mpg, I wish. I am only getting 10.

I'm getting 14.5mpg mixed city/freeway driving with 3700 miles on the truck.

dkarius-


The duals are probably killing your milage. Also w/only 98 miles on the odometer the engine isn't yet broke in.