Differences in the LM7 over the years

[69gmcc10]

I was doing some research for 5.3L and noticed that from 99 to 07 there are 3 different power ratings for these engines and I was wondering if anyone could shed some light on why. Were there mechanical changes that made the improvements or was it a computer tune upgrade?

Thanks

[Nitis]

I'm pretty sure the LM7 is drive by cable vs bribe by wire. So these were in trucks through 02?

[BR3W CITY]

Originally Posted by Nitis

I'm pretty sure the LM7 is drive by cable vs bribe by wire. So these were in trucks through 02?

The governments I deal with don't like bribe-by-wire anymore, far too much paper trail

The 99-02 were the lowest rated hp, cable throttle.
03-late 06 went to drive by wire, and I believe there was a design change near 05ish that altered the length of the head studs. I'd have to send some texts to find out why/what it changes.
06/07 is the switchover the GenIV, different heads, computer, pistons, cam, etc etc.

[69gmcc10]

The only thing that changed was the Drive-by-wire? I cant see that adding more power. So.......the power difference is just the tune the factory used?

[BR3W CITY]

Originally Posted by 69gmcc10

The only thing that changed was the Drive-by-wire? I cant see that adding more power. So.......the power difference is just the tune the factory used?

Pretty much. The valvetrain didn't change from what I know, and neither did the internals. The only things to change were the tune, and switching to DBW throttle bodies. I can't remember, but there may be a slight difference in diameter on the TB.

[69gmcc10]

Is there an advantage to DBW or is it personal preference?

[BR3W CITY]

Originally Posted by 69gmcc10

Is there an advantage to DBW or is it personal preference?

IMO yes there are advantages. You can change the pedal arm and mounting location, and when combined with the fact that you can change the pedal-sweep, it means you can mount the pedal with as much or as little "throw" as you'd like. This also means that pedal feel can be dialed in, helping "tame" wild setups for street driving.

Also, DBW is arguably more responsive than a cable or a linkage. DBW pedals can be "lighter" on the touch, and are incrementally more precise. IMO, there is no reason NOT to go DBW. It also makes cruise control a breeze.

[69gmcc10]

I am not adverse to either one, but anything to make life easier is a benefit. Thanks allot for the help everyone.