Which 6.0l Do I Have?

[gibbons948]

i have an 03 gmc 2500HD with a 6.0L. not sure whether its the high output motor or not. anyone know where the engine code is stamped?

[MS3DALE]

i have an 03 gmc 2500HD with a 6.0L. not sure whether its the high output motor or not. anyone know where the engine code is stamped?

 

Since you have an HD you have the LQ4 6-liter,It is the non-high output engine.

[omegafiler]

The 8th letter of your VIN# will let you know exactly which engine you have. It's most likely the "U" engine code, which is the Gen III 6.0l V8 (LQ4). There are also a few variations of that engine and they even made some changes into the '05 MY.

 

The GenIII HO 6.0 (LQ9) is the "N" engine code. But I don't believe the GMT-800 HD's ever get the HO 6.0. The HO LQ9 only made it into the caddy's, SS's, VotecMax's, etc.

[SS Crew]

Unless you have a half ton the only engine that you gas engines that you could get were the 6.0 and the 8.1. The 6.0 that was available in 2500HD's were the so-called 300hp engine. You really need a custom tune to wake that engine up.