I can't find these on UK sites but came across similar looking ones. However one of the reviews said "gets very hot when on constantly, keep away from plastic" ! The reviewer as a result was using them only in the indicators so it wasn't a problem as they weren't on long enough to get hot. Do your side lights get hot?
My understanding of LEDs is that they should run cooler so I was a bit surprised.
Also, I can't remember if the bulb pins are 180 or 150 degrees offset?
180 degrees. And LEDs *should* run cooler, except when they contain a resistor to activate a flasher relay. It would be better to buy ones without the resistor, and just get the electronic flasher relay. Or put your own resistor in-line, just away from the plastic lamp housing.