i have a 4 cylinder engine with two solex carburetor .my manual recommend using w200 T27, or radio shielded w200 rt 27 or d200 14/3, or radio shielded ed 200/14/3 with electrode gap of .0275-.0315. i installed a pertronix kit so i guess will go to a larger .032 gap . is a w8dc plug radio shielded ??? . is it better to use cooler plug. what is the difference between cooler and hotter plugs? im from florida so what should i use?