[Bill E]

We just retro fitted our new insolation in to a set of pipes for a CR, equipped with a 351 W, and a FFR with a 5.4 module with a supercharger. The CR before the retrofit was 315 degrees at the elbow, and 210 at the body of the muffler. After the refit 310 degrees at the elbow and 125 degrees at the body after a 20 minutes hard run. The FFR ran slightly cooler. Most of the heat in the body of the muffler was do the thermal crawl or induction from the elbow. we are working on a funalic isolator to brake the heat path. I am talking to a manufacturer to produce the mufflers for me, but for the time being We have to hand make them all. If you don't wont to get burned this is the best solution so far , short of the vacuum tube muffler we tried a few years ago.