'97 5.7 Vortec 1500 , MSD ignition installed...HELP!!!

Anybody have any experience with this set up. '97 chev C1500 w/ 5.7 Vortec engine 161K miles. Someone installed an BBK throttle body, Cold aair intake, and MSD ignition on it. It has a 6A ignition box, replacement coil, correct harness to hook into the system. It runs fine below approx 3000rpm then falls on it's face. Thought at first that it was a weak fuel pump, but a friend checked it and said it was within normal range. Wondering if anybody has any experience with the MSD set up on the Vortec. I was thinking maybe the 6A ignition box was acting up or something. If anybody has any input on this I would appreciate it.

Try cleaning the MAF sensor. It may be gummed up from the Oil off the K&N filter. I am not familiar with a 6A ignition box.

What are your fuel pump readings, key on engine off, and Key on, engine running?

By falling flat on its face, you mean it stalls, or it missfires and runs bad?

Are there any codes stored?

Give this a shot...

http://www.msdignition.com/page.aspx?id=3206

And make sure the MSD is hooked up right....

http://www.msdignition.com/uploadedFiles/MSDIgnitioncom/Support/WDTN_pn9615.pdf