tools for for boring the Elbow of the B-pipe

[pioui1]

Anybody no where to buy or the name of the extension you put on a drill to bore the head pipe of the B-pipe, the flexible extension

thank you

 

[long beach local]

Ball Hone to sand casting flaws ,polish some helps. A drum sander to open up bore On the manifold and port match It. Kinda crude but works I ordered a ball hone online and got a drum sander from harbor freight. Probably not in Canada though