My model c has the belly radiator and no provision for cabin heat. There apparently have been several arrangements for in-cowl radiators. The one that I currently favor has one radiator mounted behind the starboard-side motor mount strut. This allows a simple radiator mount, along with a very neat setup for cabin heat - just a little valve-box/dump on the firewall. But man, that rad is darn close to the firewall! Does anybody have this arrangement, and how well does it work? What are the specs for the radiator? It's clear to me that a good in-cowl arrangement will save drag and fuel over the belly rad. I'm also thinking that instead of a fixed gill to exhaust the hot air out the bottom, a sort -of variable cowl flap could reduce cruise drag while allowing for lots ot airflow for climb. Of course it would likely make removing the cowl kind of a pain. Gotta work on that. I'm not too keen on the dual-rad-in-nostrils approach. Vibration, and so many opportunities for leaks.