Quote Originally Posted by LLoughman View Post
Seems that acotyk has a point. Can someone explain the performance advantage of acotyk’s recommendation?
The ITAC and/or CRB doesn't have to explain the performance advantage of acotyk's recommendation. As I'm sure you are aware the GCR reads:
"To maintain the stock basis of Improved Touring.....No interchange of parts between assemblies is permitted, and all parts of an assembly shall be as originally produced for that assembly"
Their answer is pretty well spelled out in the introductory rules for Improved Touring.

Unfortunately the rear drums being no longer available forces the Z driver to make some choices. Race the car with available steel drums and accept the lower performance, or quit racing the car in Improved Touring.

I'll be cutting some holes in my backing plates and getting some air on those shoes and drums. I don't have rear brake ducting right now and race fine with the ally drums. I bet I can race fine with the steel drums using ducting.