I picked up a Slimline Pitts Muffler for the OS FS 70SII - It will be going into my Seagull Decathlon. I pre-mounted the muffler and the 2 exhaust tubes just barely makes it out the bottom of the cowl. Is there an extension for these exhaust tubes? I was thinking of just cutting a couple exhaust couplers to it but that doesn't look good.