Is there any way to get the pipe coated to get rid of the "yellowing" .Does heffner offer a coated pipe?
Any of the exhaust guys can have it done if that is one's desire.
To put this in perspective the Ida exhaust was developed not as an item to increase noise or have nice tips but to combat engine compartment heat and overheating. He was asked by FoMoCo to come up with a solution and was provided with information. A customer had complained and Ford was not willing to invest additional funds to correct the problem which would have required new emission testing and other legal requirements..
That is the main reason to change from the stock exhaust system; create air flow and reduce "heat soak". Bob found that he saves at least 50 hp through reducing heat soak.
There have been many threads on this subject and it has been beaten to death more than once. Suggest people use the search function, more than they do, in order to find information that has been developed and discussed almost 1 1/2 years ago.
Dave