After the run at vegas this weekend the 580hp supercharged 350 in the COPO's has been increased from 580hp to 617hp, so the 580 hp is actually now rated higher than the 590hp variant. The 590hp engine is currently rated at 616hp.
http://www.nhraracer.com/content/gen...276&zoneid=132
http://nhraracer.com/content/general...700&zoneid=132