I see that there are a few differences between the 04' & 05' Duramax like a few more HP's. Is this due to GM tweaking the computer? I guess what I would like to know is could I take my 04' in for a computer tweaking to get the extra HP since the motors are essentially the same? :confused:

Some are saying it is only on paper, if you know what I mean.

actually, the 04 LLY and the 05 LLY have the same HP just different torque, according to paper.

One of the techs made a posting a while back saying the 04 LLy and 05 share the same reflash, thus ending up with the same horse power and torque. One of the techs also did some part number comparisions of major engines components and found no differences between the two years (for the LLY).

If they do share the same parts its odd to me that, for example some people complain that in there 4.5 and 05 models have a ticking sound like an exhaust leak. I haven’t heard many other people complaining about this pre LLY. I have an 05 that has this ticking and two friends with 04`s that don’t. Not sure if this is just the luck of the draw though. Just a thought.

If they do share the same parts its odd to me that, for example some people complain that in there 4.5 and 05 models have a ticking sound like an exhaust leak. I haven’t heard many other people complaining about this pre LLY. I have an 05 that has this ticking and two friends with 04`s that don’t. Not sure if this is just the luck of the draw though. Just a thought.
FWIW my '02 had the same ticking for the first few thousand miles, but it went away just like it has on my '05.

There are 04 LB7's and 04 LLY's in that production year. The LB7 has less HP/TQ than the LLY, this might explain why you saw different numbers between the 2 years. JJ :) :)

If they do share the same parts its odd to me that, for example some people complain that in there 4.5 and 05 models have a ticking sound like an exhaust leak. I haven’t heard many other people complaining about this pre LLY. I have an 05 that has this ticking and two friends with 04`s that don’t. Not sure if this is just the luck of the draw though. Just a thought. I have the ticking also. Doesn't seem to be a problem though.

welcome to the world of marketing and sales. At work we develope several different "On-Highway Truck" ratings for various displacements, but for example a c-15 ranges in hp from 475 to 625hp but there isn't a single hardware difference. We just use the software to develope the higher ratings.

Oh and you better believe the end customers really pay out the ass for the higher hp ratings. ;)

The amount of HP you get from the reflash pales in significances to even a mild tow tune. The injectors and pump are the same. A 50HP tune will be more than a little noticeable.