I now have 2" SS pipe, but only because I had some left over from a sewage pump rail installation. Don't forget the pin slot and to drill a series of 1/4" holes the same location as the old one had. I even anti seize the cast housing after cleaning it up real well, taking care to not plug up any openings. For those who have had to remove an old rusted, corroded or otherwise ruined pipe....the 2 studs tapped into the housing to secure the feed pipe should be cleaned up real well and get a dab of anti-seize too. I always replace the square topped locking studs with Allen screw studs so that the next time, I get to save more skin! It is a challenge to not leave DNA all over the damned thing. I suppose 50 years is darned good service before repairs are necessary.......just tough to overcome those years of rusting in a hot environment.
PS: any 2" pipe will work, galvie electrical conduit (sch 40 or 80)black pipe,(sch 40 or 80). Thin wall would work for a shorter time if that is all you could find. Remember PPPPPPP, so don't wait until the holidays; blizzards; or factory vacations to stock up on spares. Keep a motor, blower coupling, shear pins, a circulator or zone valve head handy. 'Short money' for a 15 minute fix in an emergency. Beats the H**l out of a $150 service call!