A Holley 4150 HP starts out about $630 from Summit or Jegs. I've heard lots about all carb manufacturers concerning casting flash, carb bodies not machined right, trash in air bleeds. Patrick doesn't just assemble it, he tests it and flows it to make sure it performs great out of the box. Most people just put them on and it runs better than what was on it. And he gives you some guidence on changing jets and air bleeds if you choose to do so at the track. I also recommend getting his video, I understand it's sort of technical, but very good in understanding carbs.