When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
For the labor and time and seam that shows buy some already stretched. I spent a lot of time trying to get rid of the seam. I can spot it even on bad dad bags done by them.
Eastern Preformance has some nice sets.
I think you would be limited to extensions and a fair amount of trimming. MOs are a big a$$ muffler. For a fully extended bag to fit, there would be no gain in interior volume, thus negating the benefits of stretched bags. But then again, I don't manufacture stretched bags......