New in the box PRW Adjustable Roller Rockers for Small Block Ford with Pedestal Rocker type heads. 1.6 ratio rockers using a 5/16 pedestal hold down bolt which is OE for 1978-1995 5.0 and 5.8 heads. If you want adjustable roller rockers for your E5-E7, GT40 and GT40P or earlier heads and you don’t want to pull your heads and go to the expense of having them machined for rocker studs this is an alternative. These rockers are fully adjustable. You will need to check pushrod length and interference with the valve spring and retainer. These rockers are high performance parts so in some applications you may need to make adjustments to install them.