code p0303 only after road test replaced everything plugs,wires coil and sensors on 1997 Ford F-150

did intake gaskets. now after all compression tests I have 0 compression in cyl #3. code only comes back after resetting with load after 40mph also a/c switches from vent to defrost on low idle then fixs after 1500 rpms this also effects the brakes. any ideas or tricks I can do before removing head and/or replacing motor?

Asked by for the 1997 Ford F-150
No magic fix for 0 compression!! Nothing can be done externally that is.....
according to prevoius mechanic that worked on it prior to me on buying it said he did intake gaskets and it developed the misfire after the fix. do you think its possible he dropped something in the cylinder or something