Problem with Mighty Demon 750

I HATE blocking power valves. That certainly could be a contributing factor. Normally, you jump up about ten jet sizes to compensate. But see, that also takes away the fuel curve so to speak. Rather than richening up at a certain amount of vacuum, it is rich all the time. Basically made to run WOT. It's a race mod pretty much. Were it mine, I would install the right power valve and jet accordingly. BUT, remember this too.......the timing needs to be right FIRST or you'll be forever chasing your tail.