I believe that ProTrans makes them for A&A. They have been out of them for a long while. They build the Proflite transmissions that are so popular in comp eliminator and those guys pretty much consume the shafts when they are available. A friend of mine has had one them on order for his car for quite some time and he is local to ProTrans. Im not sure of what the deal is with them. Looks like someone may need to start tooling up for a product that is in decent demand. My friend Ron just snapped his output shaft behind his 904 with the 501" small block. He ended up getting a few good shafts, had them rockwell tested and then had them cryogenically treated, because the 300M shafts were unavailable. His Cryo-shafts are currently behind his big small block and he is keeping his fingers crossed.