Man does my scan look weird... input?

2004 Silverado, originally A 4.3l v6. Original PCM now controlling the V8

.040" over 350 Small Block Chevy, the engine parameters are from a 2002 Gvan 5.7L and the rest of the tune was the previous tune I ran on the truck before the motor swap.
Four bolt mains
One piece rear main
Gasket matched & Bowl hawged Vortec heads
L31 fuel injection with updated spider
CFM-Tech 74mm throttle body
K&N FIPK
LT4 Hot Cam
Proform 1.6 roller rockers
GMPP Hydraulic roller lifters
Comp beehive springs
Comp HiTech pushrods
Flat top H345NCP hypereutectic aluminum pistons; .004" deck
10.2-1 compression
Summit Geardrive
Hooker long tube headers (with O2 bungs welded on)
MSD 6a
Accel coil
March Underdrive pulleys
Summit billet distributor
3200 stall locking torque converter
Motive 4:10 rear gears
Flex-A-Lite electric fans (stand alone)

And the exhaust is a 2.5" catless Y-pipe into single 3" mandrel bent with a Flowmaster Super 40

Video of how it runs/sounds like while making readings on this scan

http://www.youtube.com/watch?v=Yby9TFEfB7I

 

It's obvious to me you have a vacuum leak on the odd cyl bank causing lean reading. Check your exhaust system on that side for leaks, loose O2 or leaky intake manifold.

 

+1 on that. i had a very leaky header and collector for a while and even i didnt see that kind of lean reading. it looks like at one point in the beginning you were at like +75%. i'm surprised that beast was even running.