Ive known a few to use Jet-Hot inside the pipes including Hubbard. The pipes run much cooler and they get the heat out of the motor better. They actually will change the tuning of the motor requiring a re-map. The coolest thing is they keep the pipes from turning blue so you don't see the blueish reflection from chrome parts on the motor reflecting the backside of the pipes.
Roy.....
As you guys probably would expect, the streetrod, muscle car, automotive aftermarket in general, uses all types of ceramic insulating coatings. Jet-Hot and HP are brands that I believe use the same basic ceramic coatings as all the other guys. Maybe they have a different blend to keep it to their name only, who knows.
Anyway, one of the many car magazines I subscribe to did a test on painted headers versus coated headers. I would think that chrome would fall into the same category as painted in that I don't think chrome has any insulating qualities.
They use a laser pyrometer and they were getting over 500 degrees on the painted header pipes and it was less than half with the coated pipes. They do help get the heat out of the motor a lot better, as to the tune of the motor with or without the ceramic coating, they didn't say in the article.
I've got V&H new Dresser Duals setting in the box just waiting for my new SERK Annie. If I wait for the PCM III to come out for the '08, I would think I'd have tons of time to get them coated. I'm not sure though if I can just coat the inside. For that matter if the pipes were bare and the ceramic coating was silver in color, wouldn't the shields pretty much cover up the pipes themselves?

Here's a picture of the headers I had on my Willys. I had to cut them all apart and then re-weld them as they were BBC headers and I used them on a 392 Hemi. I bought 2" universal bends and just cut and welded until I had what I needed. These were ceramic coated, but not by one of the big guys, it was a local coating place and they did a great job. It cost me $350 do do both headers and the tailpipes.

Here is a picture of what they looked like after one season of running the car, about 6k miles. Keep in mind that they were blasted everytime I drove the car with road gunk from the from tires. You can also re-polish the ceramic coating to bring back out the luster of the coating. I think I read somewhere they even have a "chrome" look coating.
I'm going to check with a local coating guy here in St. Louis and see if he can do the inside of the two pipes without having to remove the chrome from the pipes. I say that because I'm sure the chrome is on the inside as well, just not polished.
I'll everyone know how it turns out.
Later dudes and dudettes....