The bolt is 4 3/4 inch long and is flush on the bottom of the mounting plate that is tapped for the bolt. No clearance issues with the stock fuel rail or the rear coil bracket. Tried mounting them on a stock bracket with them stacked in pairs facing forward kind of like the original coil pack but the coils still need to be raised so the plug wires clear the back of the upper plenum. RJC has a bracket that has the coils mounted side by side facing to the outside. It looked to have difficult access to the back of the coils. With this mount, I can loosen two bolts and have access to 3 coils in just under a minute.