I have an OS 160FX with a Bisson muffler and I have a cowl on the airplane, but the tubes need to be extended to clear the bottom of the cowl. The tubes come within about an 1/8" from the bottom of the cowl and not where the bottom of the cowl is already cut out. I really don't want to hack up the opening any more, so can I bend the tubes somehow and add extensions onto it? Or would it be best to cut to Bisson exhaust tubes down and add the extensions so I can angle them back to exit the hole in the bottom of the cowl?