Which plug to run??

[Humdinger4u]

As you can see in my signiture that I'm not all stock on the motor. With having a bore of 426 which spark plug should I run to keep it cooler? I'm running a DPR9Z which I think is the stock plug?

How many of you are running a temp gauge on your motor too?? And if you are which brand and how much did you pay for it? Do you like it or not?

Thanks, Michael:)