What is the best brand of performance computer chip for a 2005 Chevy Avalanche Z71?

[Grant]

What brands are the best, not necessarily the cheapest.

 

[ramcharger]

my preference is the Hypertech Programmer, i have it on my 5.3 GMC.

 

[LS1]

well.. SLP and diablo sport worked together to make their tuners.. and since SLP has more knowledge of the LS/Vortec motors than any other aftermarket company out there i would put my money on the SLP diablo sport hand held.. just google SLP performance and you'll find it on their site.. SLP parts were factory options on many GM LS/Vortec vehicles.. only downside to their parts is they are often more expensive than their competitors