Got the HO 325hp 600tq in my 04 auto. Even has it's rating on the motor ID plate.

 

You have an 04.5, not the early 04

 

The 03 ho is a great engine have had no problems with mine. The only problem is that It is hard to get a programmer for it. My truck get 22mpg hand calculated on the highway.

 

It seems as though you're faced with two choices, from the factory that is. One is stay under the 04.5 and get great mileage and enough power or go 04.5 to 07 and lose mileage, but gain power.
For my $$ its the better mileage. I'm towing all of the time and have plenty of geddyup in the 03 HO.

 

I'm running the Smarty programmer on my '03. No problem.

Smartypower.com

 

I like the 03 and 04 HO's better for the following reasons: better mpg's, nicer interiors, NV5600 !!!, real fuse box (no TIPM? like the 06's). The major draw backs (IMO) to the 06 trucks is the G56 manual has a low overdrive gear, most of the 06 interiors have fake wood, and that silly TIPM instead of a fuse box for the trailer light circuits.
In retrospect i would have bought a lightly used 03 or 04 HO with the manual for my "play truck" instead of the 06 that I currently have, and used the extra 8-10g's for mods.....

 

Hey guys, thanks for all the advice. i have one more thing to ask. I found an 04, its an auto. how do i find out if it has the HO in it. here is the link to the pics of it. http://www.autotrader.com/fyc/img_po...9&photoIndex=0

 

Look on the drivers side of the valve cover.

305 HP is HO

235 HP is SO and may have a cat

If it says 325 HP it's an 04.5 with a cat



Best ones (in my opinion) are the 305/555 from 2004.

Good luck


John

 

i thought the 04s were just as easy to get power out of,i read that a smarty tuner would give 180hp gain on a 04.5 and up and over 200 on a 03-04.same with the predator tuner.it makes more hp on the lower hp engines but they all have the saame in the end.i almost bought a 06 and i didnt like the way the tranny shifeted{6 speed}and ya the wood dash was awful.i like the headlites better on the 06.im sure my 04 with the predator will make the same power as a 05 with a predator.just find one with low miles that hasnt towed heavy,the 06 i tried out had 20k on it but towed very heavy and 3rd and 5th gear were very noisy{worn out syncros???}i love my 04 but i wish i got a dually like i was looking for,i love the looks of the duallys with 35"tires.