These new springs are superior in every way to the old trick springs. They really shine in holding consistent at max nose pressure. If you are hearing engines turning harder than yours will turn, this is PART of your solution. This is a copy of a stock valve spring, made from a special material that has been manufactured to right at 10.8 lbs at .850" BUT Most importantly, it has as much as 2 lbs more pressure at max lift (.600", known as "nose pressure") than our previous "trick" springs. It meets all Box Stock rules and will outperform any other spring on the market today that will pass tech. Contains 2 springs.