Quote Originally Posted by dave w View Post
The SBC firing order is 1-8-4-3-6-5-7-2.

The 5.3 liter (LSx) firing order is 1-8-7-2-6-5-4-3.

It's my understanding changing the '0411 bank assignments in the flash, DOES NOT change firing order. The '0411 24x firing order can be changed by re-pinning the Injector and Coil Pack wiring.

dave w
BOTH need to be done. Injector bank assignment and diagnostic firing order need to be changed in the tune and both the injectors and coils need to be re-pinned at the PCM. Easy way to correct those is copy in the table values from a 5.7 Express van tune. I am running my 5.7 on a modified 6.0L tune in a 1 meg PCM (Green/Blue connectors).