What's your altitude there? I moved from Albuquerque about 2 years ago which is at about 5500-6000 feet above sea level. Trust me, I feel your pain!

You may want to look into your accelerator pump nozzle size and step it down a notch or two. Remember, you are dealing with less dense air at higher altitudes so that initial charge from the accelerator pump may be too much now. Your powervalve should still be ok. I still ran 6.5's on my holley even at 6000 feet, but again, it depends on the vehicle too. You may have to drop it down to a 5.5 or maybe lower depending on your cam and vacuum signal.

And just for good measure, check your float levels before you start anything else. Alot of times that ends up being the correction.

Hope this helps!