Theres a couple of guys in NC near greensboro who swear by them in Carden Extra 300...
Another great plane for this engine is the Midwest Cap 232. The engine fits beautifully within the cowl including the plug caps on a CH ignition. I believe mine was about 15# dry.
Jim Goad (who owned Indy RC and used to sell Tartans) is also knowledgeable on the engine. Last I heard he also transplanted to Florida.
Incidentally, Jim Cline's website for Tartans and Tartan parts is here:
http://www.billsroom.com/pcfs/