Yep, that's a genuine GM precision alignment tool for the proper installation of the front cover. There's one for the rear cover and oil pan, also. I use the poorboy method, put the cover on loose, draw the crank pulley on, install the oil pan without the gasket and snug it down, loosen the cover bolts, tighten the bottom bolts through the pan into the front cover and then tighten the cover bolts to specs. I know it's not the recommended way to do it but I've never had a leak anywhere but a valve cover gasket that fell out of the groove during installation.