Push rod guides? They automatically make the push rods too short, and the push rod studs too tall. Anytime I put guides on a small block, I get longer pushrods. The screw-in studs are the right height when replacing the pressed-in studs with the screw-in type. But when you raise the stud by putting the guide underneath, the rocker arm will only adjust sooo far before the nut bottoms out. Measure the thickness of the guide, then order new push rods the appropriate length. It's my guess that the cam and lifters and rocker arms are probably fine.