411 swap

[Enigma540]

Are you positive the ecm was flashed with the 7.4 file? Seems like most of the express vans were 5.7 vortec and ls based. 7.4 vans, I'd think, were pretty rare.

 

[L31MaxExpress]

Are you positive the ecm was flashed with the 7.4 file? Seems like most of the express vans were 5.7 vortec and ls based. 7.4 vans, I'd think, were pretty rare.

7.4 vans only had the black box. By the time GM put the 0411 in the vans in 2001 GM had already moved on to the 8.1 in them.

 

[Christian Steffen]

I believe he got it going, he used a computer from a suburban and the tuner didn't switch to the correct OS.