Also I haven't weighed it yet nor did I get any rpm readings, was spending most of the time trying to figure out why she was flying that way.

I have a friend who has a brand new Bisson muffler made for the mvvs 58 that he wants to sell to me for 50 bucks. He has that engine on a warbird with a custom exhaust so he never used the pitts. I will try to pick it up from him soon and check the rpms and sound with the new muffler.