My original Hooker Super Comp had the same issues on my 73. I didn't realize that the installer had cut and welded my mounts to get them on. I know the Comp headers will go in ok but with the new Super Comp if you raise the motor with a hoist and remove the mounts they will slip right in. Then replace the mounts and lower the motor back down and you don't have to modify the mounts at all.73 has the different motor mounts. I think I have headmans and had trim the corner of the mount to make clearance. drivers side.