According to that they have a 1.78 installed height and a seat pressure of 132 pounds. The 981 Comp springs have a 105 pound seat pressure at an installed height of 1.7, so no, it probably wont be plug and play. The only way to find out what's needed is to mock up the comp retainer and measure that height. You can add shims, and they also make keepers that move the installed height up or down .050 inches. For break-in I'd just take the inner springs out, you can also call Holley, they might be able to give you the spring rates of both the outer and inner spring, it's possible that the rate of just the outer might be close to the specs on the Comp springs.