Dave it is good stuff.
The Trike had this treatment on it's headers up until 4 years ago when i went with the Sanderson Headers for it.
Sanderson also has some inside coating, not sure who, but the header gave the big Chevy about 40# more torgue. Enough it will lift the front wheel on a off idle stomp about 14 to 20". Raises hell with fork seals however.
Here is the latest setup. 4" Nascar setup.
