Those were part of the LIVP kit in 2000.
Ralf, sounds like you are referring to exhaust tunnel extensions.
you can get these through Mike Custard at 541 330 5817
I think Dan Begley actually owns the molds but I don't have his20contact information.
When I got mine (2005?) Dan was charging $1000 for the pair.
I will say that they make a dramatic improvement in cooling, possibly at the expense of additional cooling drag. It might be less drag to make something like them but taper so that the exit airflow is approaching slipstream speed by the time it merges with the slipstream.
Colyn
One more question: I saw some kind of side skirts on the demonstration airplane (see picture attached). They were right where the exhaust pipes come out. They make a nicer visual transition between the cowling and the fuselage. Lancair told me they don’t sell them but they are made by RDD or Mike Custard. Does anyone have a contact address and a price on these pieces?
And as always: Thanks for your help