Competition Cams 4797 Crankshaft Socket for Big Block Chevrolet<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>For Chevrolet Big Block</li><li>1.610 inch ID with 3/16 inch Keyway</li><li>Specially designed 1/2 inch drive socket allows rotation of engine assembly</li><li>Knurled retaining nut that holds degree wheel in place</li><li>Can be loosened while on crank snout so that wheel can be turned independent of the engine when finding TDC</li></ul></div><img src="http://ecx.images-amazon.com/images/I/51L4jYyY-hL.jpg" noproxy><img src="http://ecx.images-amazon.com/images/I/514oXWddkKL.jpg" noproxy>