Running schedule 40 black steel pipe through concrete foundation wall
Gas lines running underground to a house are supposed to break the surface of the ground before penetrating the  wall and entering the house. This is so that in the event of a gas line leak under ground the leaking gas will follow the pipe to the surface and be expelled to the atmosphere instead of inside the house. Check with your local gas company to see their requirements for running a new line, wall penetration sleeve if required, type of pipe to be used, and are you allowed to run this pipe yourself. Installation codes change with city, township, county, etc. You do not want to replace the line and find out something was not done correctly and it has to be redone. Where I live the codes are strict and you must follow the codes to the letter. So again, call your gas co. and ask first.  Anyway the 1 inch pipe has an ID. of 1.315 inches which should slide into 1-1/4 inch schedule 40 pipe that has an ID of 1.380 inches.