What all did they do to the Cummins in 2004.5?

I have a 04 truck the engine tag says Manufactured 2-10-04 but has the 325 Hp at 2900 is this the late motor or the early one and what all is the difference?

When I look at Programmers will it make a difference I am thinking of the Smarty Jr not really looking for Race manners just a few extra ponies and better MPG

Thanx Joe

 

i was told the if the truck has the 325hp and a cat conv under it its an 2004.5 and if it has the 305hp and no cat it was a 2004.

but i may be corrected if wrong

 

04. 305 was the HO. Turbo is the HE341. 04.5 325HP and a cat. HE351 turbo. If it has a cat, its 04.5

 

If it is a 325hp engine, it is considered a 2004.5.

There were a number of changes, among them is the turbo wastegate is electronic on the 04.5 and the exhaust is 4" front to back too.

 

Yes, 325hp is 04.5, when you order a smarty or whatever performance add-ons you need to order them for an 04.5.

 

Build date of 01 Jan 04 is 04.5.

 

Other than the turbo size, waste gate being electronic and having a cat is there much difference in the engine? I assume that the boost is controlled by the computer if its Electronic. I am familiar with the 12 valves but am new to these Common Rail engines. If there is a good place to look or a good write up with lots of info on these engines let me know where to find it.

Thanks for the replies

Joe

 

spray angle of injectors is different. but basically the big ones are cat and if its the 325 model.

 

Doesn't sound like there was much point of spliting the year. they may as well have just build the '03 -305' right to the end of Dec. then introduced the 04 with the 325' in Jan. would have saved a lot of confusion.
what was the point for a few small people to gloat they bought there '04' in late 03. then they all got there hopes dashed when the 325 came out

 

05 Ram,

They did build the 305 until the end of December '03 and it was called the HO. As of Jan 1, '04 the emissions requirements were different so the 04.5 model (starting with a build date of Jan 1, 04) had the cat and some other changes to meet the new requirements. They are referred to as the 04.5 model.

They start building the new model trucks in about August. So from August '03 till December they built what they called the 2004 model. We here refer to the later ones built after Jan 1 as the 04.5 but they are registered as 2004 model year trucks.

The 04.5 model has the cat, 325 HP and gets a little bit less fuel mileage. Some of us prefer the '04s because they have no cat and get better mileage. Some prefer the '04.5 because they have more factory HP. My hopes weren't dashed when I ordered my '04 and found out the later ones had 20 HP more. I specifically ordered mine early enough to get the '04 because I didn't want the extra emissions stuff. Now, with a Smarty, that HP difference means nothing.