Hi:

Timing of 477 is 6 degrees BTDC at 550 rpm for gas and 10 degrees BTDC for LPG motors. Additonal information can be had in topic 477 Firing Order and Cylinder Number on this board.

Cylinder head bolts are to be torqued to 170 - 180 Ft-Lbs in three stages. first to 140 then to 160 and then to final value. Also the bolts are tightened from the center of the head out and from the intake side to exhaust side. So center intake bolt to 140 and then center exhaust bolt then move one bolt to front and repeat then move one bolt to back and repeat then front bolts then back bolts. Repeat to 160 and then repeat to final torque.

Trust that helps.
PaMnd