I just put a 2006 LQ9 (Vortec 6.0) in a 1956 Chevy and I have no spark.

No Codes. All grounds look good.

Can the VATS prevent spark?

I was under the impression I could fire the thing up and the VATS would shut the engine down after 3 seconds so I could at least make sure it runs before I program the computer. I have not got the VATS removed from the PCM yet.

Thanks for any help.