My 2010 FLHTCU with V&H Dresser Duals and the new Rinehart 4" slipons, V&H FuelPac, Arlen Ness Big Sucker stage one air cleaner. Major difference in heat. I show it to run 20 degrees cooler using an infrared temp gauge using AMSOIL 20/50 and Amsoil Severe Gear 75/110.
IMHO, not enough testing has been done on air cooled engines running CATS. I bought this bike new in Tallahassee on vacation after my 07 RK lost a tranny and before I got down to Tampa I thought I was going to have roasted oysters. Took off the lowers to get more air on the engine with no appreciable results. Rode back home to Illinois and change the pipes right away...WOW what a difference in the way it runs, starts, fuel milage and the difference in how much cooler it runs blew me away. Now I have a beautiful Ultra that I can love to ride without getting sterilized.