How do you desiced on new plugs?

[mikes68charger]

I have a 360 new with 9.5 comp hyper tec piston, 2.02 in valves, with roller rockers, Weldon single plane with a 650 eldrbock ASV carb, 4 speed with od, 391 pos in the rear. I'm running election ignition, with the chrome mopar box, thinking of a MSD set up. SO how do you chose the write plug? I was told theres diffrent temp range, and they sell the E3 spark plugs at pep boy, look fancy but will it make more power?

[dodge freak]

It might with the Mopar unit but if you go with MSD they say to use only Standard plugs , no platinum or other fancy plugs. Something about the hotter spark will over heat and wear out those plugs very fast. For heat range MSD says to go 1 or 2 ranges colder-for your motor 2 steps colder sounds right.

[Ghoste]

  I'd follow the same advice even without the MSD.

[myk]

I uh....bought what they had on hand for me, which were Bosch Platinums-no multi-tip deals, just a single tip.  I THINK I'm o.k. so far...

[mikes68charger]

OK, stupid question. How can you tell if they are a colder or hotter plug?  How dose the part number change?

[dodge freak]

Yeah thats a good one-some plugs as you go up the last # it gets hotter but some-I think-get colder. Its best to call the plug manufacture - once you know what brand you like to try-and ask them , cause sometimes people get mix up.

I do know for sure that Accel plugs the last # is it. As you go down the plug is colder. For my small block 116 is the stock heat range-not plug cause its non-resistor, so to go colder you want a 115 or114 they go down to 112 I think.