i was wondering what are all differences between the 03-04 CR vs. the 04.5+ CR i mean advantages, disadvantages, which responds to what performance better, etc?

 

I think the 05 seems to be about the best year to mod. they have the most available for them. programs like crazy larry wont perform well on 03/04 trks. I have owned and 05 & 06 they seem to do well with the mods on them.
but there are tons of 03/04 trucks on here with big numbers. the most I know of is 808 and 822 on diesel fuel. in the latest diesel power I got today there is a mega cab with claims of a 1k hp with water injection.

 

03-04 have no emissions crap on them at all, the 04.5-07's have a kitty. The 07.5's have everthing but the kitchen sink as far as emissions go.

 

thats a good point danram. the cat comes off pretty easy. for off road purposes only of course. I wont buy a 6.7 with all the emissions clogged on them. none of the brand new diesels appeal to me. I will keep mine

 

03-04 also dont have the 3rd injection event
ie: cooler egt, better economy etc.

03-04 still have the 5600 not the g56 ie: better overdrive

 

I have owned both. Got 21-22 mpg consistently with the '03. Sold it, got and '04.5 with 50% more electronics and a cat. I'm getting about 17-18. Wish I kept the '03.

 

the nv5600 was put in trucks until 2005. I had one in my trk. that is a good point though, I hear the g56 is weak. the 5600 is strong it held up to 500hp in my truck. ive seen some 05.5 trks that have the g56 trans. my 05 got better fuel mileage than my 06 does. the radio was way better also along with the interior I think. my dash came apart a while ago and the abs module went out.

 

The '04s always get better mileage. No cat and no 3rd injection event. Also they have the mechanical waste gate. All the internal goodies of the HO but simpler overall. Whenever I think about a new truck it's mainly about the new tranny, not the new engine. But then I come to my senses and am glad I have the '04. Someday though, I'd love an Aisin conversion. Dream on. I just can't imagine how the engines could be any better, in any year, unless it's pure simplicity you're after, like the 12 valves.

Wetspirit

 

The 03/04 ran a different turbo than 04.5 up along with different size downpipes. the 04.5 makes more boost than 03-04.

 

My '04 is from California and has an nv4500, and my mileage blows. I get about 14.5 90/10 hwy/city. If anybody knows a good way to get this ISB 235 to run, let me know.

 

i like the fact that the 03-04 has a throttle cable, the 04.5- 07 have the throttle positioning sensor and no throttle cable, call me old school but i am not a fan of the sensor activating my throttle. yeah the 03-04 throttle cable assemblys look more cluttered than the 04.5-07 but i guess there is give and take with everything

 

I have buddy with the 305 "04 and it is a great truck...great mpg's/ power its a good blend of the best of old/new school. I think it may be the best yrs for a used one........with the 06-07 with the 5.9's as a close second in a few yrs

 

well those huge tires killed about 1.5-2 miles per gallon.. you need a good dowloader to get your engine running more efficient.. Once you do that, and keep your foot out of it, you will see mileage come up. If you just want mileage, the Big G plug and play box guarantees a certain amount of gain, so if it doesn't get you that much, send it back for a refund.

 

thats a rebadged Quadzilla Box

 

I believe the 03-04 have a valve seat problem when exposed to high egt's for long amounts of time. Had a 05' and now have the 04(305). The 04' runs lower egt's, and better mpg's. Both had 6" stacks and the 04 sounds better, no rasp to it.