Anti-friction additives for the oil do wonders as well. I have used them for years in various applications. I am currently using one made by Justice Bros.
It is hard to find unless you can locate a distributor for them.
This stuff has been good for a 20-30 degree reduction in temp in most everything I have put it in. Not to mention the added bonus of reduced wear and how much smoother the engine runs. My S4RS ran way beyond hot when in stock form (lean) and adding the additive (after breakin) reduced temps by the avg mentioned above. Then I added the full Termi system w/ ecu and temps are no longer an issue... ever!
I hear the Lucas brand is awesome as well.