I'm running a solid 350 chevy (well it used to be anyways...) about 300 hp, and have turned it up to 5400-5600, but have been told that is over the edge. I am getting ready to freshen my backup motor for LaborDay and hoping to make a few more ponies than the current motot had, so we'll see what happens.
If it kils the drive I suppose I can put a jet on it without too much extra work, and still be cheaper than a "good" 800.