Anyone use Autolite XP-103 spark plugs?

i'm trying to find out what the heat range is on these things. Autolight says the heat range is 3, but im not sure what stock is for heat range. Anyone running these? I'm looking for plugs that are 2 heat ranges better than stock. I know the tr7ix are, but i cant find these locally; however, i can get XP103 plugs tomorrow. Can anyone help, i've searched and searched but i just got a headache from it. They seem so new that i cant find any info on them.

the98stang said:

since you have a v2 blower you can use NGKtr6 plugs which are 2 step colder and AWESOME plugs for forced induction....way better than auto lites IMO

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We'll those are only 1 step colder and im currently using those. I keep getting spark blowout and The car has been rugish with them. I replaced a couple of them, fixed the rushish ride, then 3kmiles more its back. I need a better spark plug and soon. I want the iridium because there a stronger plug. For some reason my engine does not like the TR6's I think there to hot for my temps. When it was 60-70 outside it was fine, but once we hit 100 here in cali it hasnt been driving right, and with out continuous hot weather its time to get a colder plug.

If there is any iridium plugs locally i can buy that is 2 steps colder i would prefer to do that. If im stuck buying online it'll be the TR7IX plugs, but that will take a week to get.

Any other recommendations?

Thanks guys, but i gave up looking. I just ordered NGK TR7IX online with 2nd day shipping. Amazon.com was actually the cheapest online after shipping.