I just replaced mine a few weeks ago. The brass tubes were available at the first place I checked (boathouse Marine). I believe they were 1" X 3", but I checked them by sticking my finger in them on my boat, and then at the store - perfect match. This same place rented the flaring tool for $2/day. It is just two pieces of machines steel on either end of a bolt/nut that tightens down to flare the ends. Not exactly sure of your boat set-up, but I had to remove the panel in the bottom of the transom so the old tubes would slide out as I beat them out with a screwdriver from the outside. You may be able to do it without removing that panel, but I had taken my engine off to replace steering, so it made everything easier. I also took the extra step of epoxying the transom holes before installing the new tubes. I also replaced the one at the bottom bilge drain. I used ample 4200 during install, and it turned out nice. Not really a rough job. In the weeks prior to this, I also replaced all of my thru-hulls with SS fittings, but that's a whole other story - not fun.