I have been reading about the turbo mufflers being restrictive. How bad/good are the non-turbo mufflers? I purchased a set of mufflers from one of the vendors, and have not installed them yet on my 140. Would I be gaining much by going with a more free flowing muffler on the 140? Thanks! Ron Tinkham http://www.ronsjeepjunk.4t.com/ Pine Tree Corvairs (in the works) 66 Corsa Convertible, 140, 4sp Maine