OK, guys. Someone fill me in. What is the difference in the 04 and 04.5's? Is it just the H.O. motor or something else, thanks.

 

The 04 is 305 HP and 555 TQ and 04.5 is 315HP and 600 or 610 TQ i think. Thats why the 04.5 some of them have the 600 badge under the 3500 badge on the side i guess.

 

305 vs 325 hp, 555 vs 610 tq. 04 does not have cat, 04.5 does. Something else too, but I cannot remember. Electronic wastegate?

 

Iconel valves and high cobalt Stellite exhaust valve seats, diferent porting for less "swirl", bigger turbo compressor wheel and electronic waste gate, new lift pump.
Diesel Power Mag April 2006 Pg 120
Mike
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Yes as stated above pretty much a different engine, different computer programming and apples to oranges for most mods.

 

04.5 (600) has a cat, the dreaded third injection event and computer controlled waste gate. 04s (555) get better mileage and have no cat. I thought the 04 HO and the 04.5 HO were the same internally with gallery cooled pistons, bigger oil pump etc?

Wetspirit

 

Ok well I guess that "completely different" was a little stretch. Somewhat different physically and programatically. Modding physically is pretty much the same, but programatically quite a bit different. Results of the same mods seems to be different also.

 

So if you have the 04 with H.O. motor it is considered the 04.5???

 

The 04.5 has 325hp/600ft/lbs. Both have the on the filter LP unless they have gone out and then they moved them to the tank. The valves and seat upgrade is due to the higher temps from the 3rd injection event and the cat caused by emissions reasons. The 04 HO is the 305hp/555ft/lbs. Some one else will pipe in about the SO motors. Lower hp and Torque.

 

No, the HO or the SO were available in '04 as '04 models. After Dec 31, 04 all trucks were '04.5.

Wetspirit