500, 472, 425, 368 Discussion, rocker arm bolt -- IMPORTANT I NEED IT in Cadillac Engine Technical Discussion; hi friends
i've a problem... in the service manual was written that i should tighten the rocker arm bolt with ...
Heres the story... In 1980 they changed the rocker arm set-up on this family of motors...up to 1979 they used one bolt for two rockers on one cylinder.. in 1980 they went to one bolt for each rocker... and printed the wrong torque specs in the manuels after 1980...when they were one bolt for two rockers they used a 7/16" bolt [about 11mm] when they went to one bolt for each rocker thy used 5/16" bolt [about 8mm] ... so the torque for the 5/16" bolt
is about 20 foot lbs... If I were you and really needed the car I would get a thread repair kit, we call them heli-coils here, and drill out the threads and make them 8mm and get the highest grade bolt you can and use that..