Not that I have, but what harm can come, if any, during a race to run open headers? If I recall my reading, the 5.0 depends on back pressure to produce the best horsepower? I see a lot of pro-street cars running with open headers, what is the overall advantage of doing this?
Back in my day the long tube headers were usually run open at the track. Of course we are talking about another 100 or so cubic inches and a couple of points higher on the compression ratio. With the shorties that the Mustangs come with you do run the chance of burning a valve.......................now with the long tubes I would think that you would be ok. We did have to bump the timing and rejet the carbs when running the oepn headers.
With the proper engine combo, open headers can be an advantage. However, in stock form the car needs an exhaust to maintain a useful powerband. Open headers would destroy this.
in anything near stock trim (i would even venture to say that a HCI car would be included) i bet you would see a decrease in power (especially low end) by running open headers...LT's probably wont cause any damage, but with shorties you will probably burn valves...but if you have a stock or minor bolt on car the car will feel like a DOG with open headers....