I have 6 rebuilds on my 572 aluminum World block, it leaks 0-2% and did after 142 passes with Predator heads. I also have a 604 Predator on a steel block, with 2 carbs and more camshaft. It won't keep up with the 572 with one because of weight. Not much more I can say. You won't make up for 150 pounds of weight, bottom line.