My daughter has been riding with me more often and has got confident enough to max out her '78 express. Upper 20's MPH isn't cutting it anymore. I'm pulling it apart this winter to replace the seals, gaskets, hone, new rings, upgraded reed, etc. I would like to swap out the carb and pipe at that time. There are two MLM pipes available but they're sold out. What other options are there? Anybody got a used one to sell?