Autolites, and you don't want anything but Copper.
I asked a ref if he could give me a technical foul for thinking bad things about him. He said, of course not. I said, well, I think you stink. And he gave me a technical. You can't trust em. -
Copper, basic, Autolites. So you have to change them every 30k, so be it. There are other things that need done about that time anyways - brakes, lube the dizzy pad, etc.. These vehicles were not designed for long maintenance intervals.
Those fancy plugs are just that, a fancy plug. Bosch Platinums have the anode flush with the ceramic, shrouding it to a pinpoint piece of metal. They foul easy, too. The plugs with the multiple ground straps (electrodes) just shroud the center of the plug too. I was always told that you need a high turbulence chamber for those to get the best air/fuel charge into the gap for the spark to get it. The example of the high turbulence they were talking about was turbochargers and superchargers.
1978 CJ5 5.0HO/T177/D300, '86 D30/D44 WT axles, 'glass body, 31x10.5 BFG A/T, TDK galv'd frame - DD and weekend toy
..So you have to change them every 30k, so be it....
For whatever reason, I have always found that changing spark plugs was somewhat theraputic. It gives you a chance to see what's going on inside the engine, it doesn't have to be done that often (assuming you don't drive 60,000 miles a year), it's cheap, doesn't take too long, doesn't require that you get under the vehicle, and on a Jeep (any many trucks and cars), the plugs are really easy to get to.
"I give you a republic, if you can keep it." - Benjamin Franklin
I wouldn't put Bosch spark plugs in anything. I have 2 friends who both had bosch plugs that broke and created major engine problems $$$. Even after a letter from the mechanic, and some pics, stating that the plugs were the cause; Bosch wouldn't pay a dime of the several hundred dollar repair bills. I refuse to buy any of Bosch's power tools also, or anything with their name on it for that matter.
I use 985's in mine, but have used Champion's in the past.