Put the cam gear back on and use a strap type wrench to turn the cam gear or a square sided screwdriver between the cam gear bolts and the nose of the cam.

Only unbolt the rocker arms when they are in a position without any valve spring tension on them, rotate the cam as necessary to achieve this position. The threads in the head for the rocker arm assembly bolts are weak and susceptible to stripping. Revised/longer bolts were available to counteract the stripping. Use a torque wrench to re-install them and only tighten them down when all valve spring pressure is relieved on the assembly being tightened. Be careful with the front rocker assembly to capture the half moon piece that controls end play of the camshaft.

Keep everything in order and watch for the little cups on top each valve. They are easy to lose.

Everything will have to be in time to re-assemble, when rotating the crank to TDC keep upward tension on the chain so it does not get bound up.

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"Rudeness is a weak man's imitation of strength" - Eric Hoffer