BAD lean spot.... any suggestions??

Thanks RedFish. The EGR has only a vacuum port and appears to be fine. I recently bypassed it, removed it and made a temporary gasket to insert under the EGR from a beer can. No change resulted. The vacuum diaphragm seems to hold vacuum with a handheld vacuum pump. When connected I can move the EGR and make rpm changes with the engine, so I believe it is good. As far as the OASC, I have it bypassed so I am taking vacuum directly around that. I am not sure if the solenoid is good or not. The temperature sensor is currently reconnected and grounded to the top of the engine block with a clip lead jumper. Where is the fuel vapor valve? Is that to do with the charcoal cannister set up? All I know is it seems like a "lean" issue, since when the truck is ON CHOKE it does not exhibit the bucking symptoms under load until it is warm.
Thanks again!!