350 engine keeps bogging out when driving esp. from complete stop?

Just a long shot but what transmission do you have? If it is the 700r4 try adjusting the tv or throttle valve cable this determines when the line pressure in the trans builds up . If not adjusted correctly it will cause late or early shifting depending on throttle position . Just push the on on the end of the cable hooked to the carb and it should release tension on cable then . Push the gas pedal to the floor and release the on on the cable as it adjust you may hear a ratchetting or clicking sound after you have adjusted the cable take it for a spin and see how it drives hope this helps .