Whats the difference between AC Delco Rapidfire plugs and AC Delco platium plugs? can you still buy or get the rapidfires? and also can you use the Platiums in 92-95 CPI motors with getting a misfire?

AC Delco Rapidfire = copper electrode with nickel ground strap
AC Delco Platinum = platinum tip on both electrode and ground strap
AC Delco Iridium = iridium electrode with platinum tip on the ground strap

Platinum does not erode like the copper does which gives the plug longer life and because it is a smaller area, the spark is more controlled.

Iridium does the same basic thing as Platinum, but with an even finer electrode tip, the spark, again, is more controlled.

Hi Kyle
check out this AC Delco link: http://www.acdelco.com/parts/sparkplugs/
i think there is actually 4 type of spark plugs...there's a regular copper, then next is the rapidfire with platium electrode tip and regular ground strap, and then the double platium, and then the Iridium...is this right? also is it true that Autolite makes the spark plugs for AC delco now?

Yeah, I know there is. I would never consider the platinum tip with nickel ground electrode because the only benefit over the regular copper plug is a more controlled spark. They are on the same level in terms of life and I wouldn't consider paying more for that.

Has anyone ever used an NGK plug with the 4.3? I have to get new plugs soon so I've been searching around a bit. I found a lot of Bosch ones (which I will stay away from) but also some NGK ones. I've heard good things about the higher end NGK's, but they also make a pretty cheap one too. I'm thinking the cheap ones are going to be crap? Here they are on autopartsway: http://www.autopartsway.ca/autoparts...or%20LS~240800

well setting aside the cost factor, and that was not an issue at all cause your buddy has all of them, which plug would you pick or recommend in your opinion? which would cause the least amount of misfires? and can i even run platiums in my 95 CPI "W" motor? and is it true Autolite and AC Delco's are made from the same plant and tooling? only asking because some guy i came across says he works in actual the plant and says they are the same plugs just different labels are put on them depending where they are going. so i just wanted to confirm if you heard the same thing?

You should be able to use the double platinum or the premium iridium plugs with good success. I have used the AC Delco & NGK premium iridium plugs in a few different GM vehicles with good results.

And the plugs are very different. I like Autolite's copper plugs and run them in my 350's, but those ignition systems are not as hot as the more modern vehicles. For the newer GM's, stick to AC Delco.

.060 gap if i remember right

thanks for the advice. i have a brand new set of AC Delco CR43TS plugs that my truck actually calls for however im gonna wait to install them until i replace my spider,fuel nut, and lower intake gaskets when the weather gets better. this way they dont get all fouled up. but for now, temporarily, im gonna try the Autolite double platium single ground strap plugs since they wont cost anything and this way i can get out those Bosch +2 plugs out of my truck....

+2 heat range?