The first thing to remember with a stock engine is everything is setup and tuned to meet EMISSIONS!! They are setup so lean and restricted that heat is the only result.
You will need to get rid of the restrictions, air filter, cats, exhaust pipes and then retune the engine to the proper AFR for a Harley engine. That has never been 14.7, Harleys prefer, almost demand an AFR between 13.5 and 13.8. Under extreme load, the AFR may have to be as low as 12.5. Set up to actually run (not meet emissions) they will run far cooler, everything lasts longer when its not being fried!!
Get a tuner like the TTS, find a competent guy to do the tuning, change what needs to be changed to unrestrict the system, the engine will run way cooler and be much happier.
My S&S T124 typically runs about 185 on 80degree days, highest I've ever seen is 210 on a 104 degree day in Sturgis, and that was stuck in traffic for 40 minutes. It has the small 5 row oil cooler I installed in 02'.
The work begins! FWIW twinotter
