CR10EK spark plugs at high altitude

[NMYami]

I did a search and was not able to find any information about using CR10EK plugs at high altitude. Whould it be safe to run 87 octane fuel at high altitude (10000' +) with CR10EK spark plugs on an Apex Mountain with an aftermarket exhaust? I read that the Apex shows the most horsepower gain at 87 octane with the CR10EKs. Would it be safer to use 91 octane? Would the 91 octane fuel negate the horsepower benefits of the CR10EK spark plugs. Any help you all could give is greatly appreciated. Thanks.

 

[pro116]

It will be plenty safe running cr10ek's are more safe then the stock plugs they run cooler.
Running 91 octane you will just be losing power and wasting money.

 

[rideblue]

Been running stock CR9E with 87 at 10,000+ ft with out problems