MSefi.com read only forum (Jan.15,2018)

When I'm in Park it will idle around 900ish RPM and be around 14.4 air/fuel.

When I shift into gear it will stumble almost stalling, than idle around 600ish RPM. It will be around 14.4 or 15 air/fuel.

Is there ANYWAY to make it so it won't do this? I hate having it almost stall. I'm using a chevy IAC. as well.

You could try running more advance in the lower RPM bins to try help the engine recover. I run a mild roller cam in mine and it idles at about 900rpm in gear and about 1200rpm out of gear, I find that the engine loves ignition advance - similar to running the old manifold vacuum advance. Also your idle speed should be set while the car is in gear, no different as you would if you were running a carb.

I'm not controlling spark at the moment. But do plan to do that in the near future...perhaps over winter.

I seem to have it switching better now but still dips down to 400ish rpm which i do not like. It doesn't stall though.

Try adding more fuel, it's almost as if the engine isn't producing as much idle torque to cope with the gearbox once it's engaged in gear. Also once the engine is thoroughly warm, turn up your idle speed to about 800rpm whilst in gear and see where that gets you.