GMT800 pre-facelift and post-facelift performance differences

[Rusty Dusty]

Hey there and greetings from Poland!

 

I have a 2002 Tahoe with a LM7 under the hood - a truck I like so much, that despite the fact I bought it to haul my recreational/sport stuff, it pretty much ended as my daily (spring till autumn). I have read somewhere (and kinda confirmed it just a few minutes ago on Youtube) that the post-facelifting trucks ('03 and newer) are faster than pre-lifting ones. I mean 299 vs 273hp and 9,0s to 100kph (62mph) vs 12,0s. My Tahoe really does the 62mph in a pathetic 12 secs. 

And now the question is: how to make a '02 truck as fast as a '03 one? What were the changes? And how did they manage to cut off a whopping 3 secs by adding just a small amount of horses? It's only 26hp more. Is it only tuning or is it something else? It would be nice to get a bit more in return for feeding this always thirsty V8.

 

Cheers!

[shakenfake]

6.0 swap.

[Vanaj]

Could be just the difference in the rear end gear ration.

My 02 1500 Silverado LT 5.3 with 4.10 gears is much faster/quicker than my 00 1500 Silverado LT 5.3 with 3.73 gears.