BRAND NEW TO THIS SITE. JUST FOUND A 1956 GMC GVW=21,000#. I BELIEVE ITS I6 GAS ENGINE IS THE 302 C.I. OF WHICH SEVERAL SPOKE. ALSO HAS 5-SPEED (5=DIRECT). CANNOT FIND TIMING MARKS, FIRING ORDER. PLEASE HELP! NOT RUNNING, BUT TRIES TO FIRE. 12-VOLT. FLATBED. APPEARS TO BE EX-MILITARY. HAS GRILLE OF EXPANDED METAL FRAMED BY FLATBAR. WOULD LOVE ALL ADVICE! THANK YOU.