For a little extra boost, add this ATI pulley for solid gains with the advantage of less belt slip doing so. As you may have noticed these are priced a little higher than the competition for one reason, we have these shipped in with the second keyway added to the hub, this along with double pinning crankshaft is sure to keep pulley in it's place. Be sure to add in the drilling fixture if you do not have one and new crankshaft bolt as they are one-time use. The drill fixture comes with 2 crank pins as well.