These are the Blower Grinds from Comp Cams I see?
"Hotter cams" often seem to give problems with modern engines. Mostly because the modern MAF or MAP sensors get mixed-up readings due to the inlet pulses. For sure the more experienced NA tuning guys can shed some light on this.
The LSJ SC manifold is for this not very good because it has no runner length at all. :problem: And the sensor is placed directly in front of cilinder 1 inlet port, so I think this might be part of your problem. For more even readout you should move it further away from the inlet ports, only there is not much space to move it to. I can only think of somewhere in the bottom side of the manifold...
I can be totally wrong here off course, but sometimes you just have to try these things out. :ugeek: