Rocker arm pivot torque spec or valve lash????

[72timemachine]

My friend has a 72 Chevy truck with I believe to be an early 80s replacement engine, the factory color of the heads, block, and valve covers are black.

Anyway the rocker pivot nuts have the nylon on the inside of the thread to stop them from coming off. One day we heard this louder than usual ticking so we pulled off the driver side valve cover and the rocker arm was very loose.

How should we go about adjusting all of them, get the motor hot, and bring them up to 0 degrees tdc and check the lash or go by torquing them down by a foot pound spec?

Sorry I did not look at the casting date at the rear of the block but if necessary I will post it.

Thanks for any help.

[dwcsr]

You have the wrong nuts on the studs. You need "Prevailing Torque " Nuts. What you have are "Elastic Stop" nuts. The rocker nuts do not have a troque spec. Its usually back off till they make noise and then tighten till it just stops and then half to 1 turn depending on who you ask. I do half turn. 1/4 at a time. You should be able to get the right nuts at the parts store or jegs or sumitt.

[Ticker]

Two thoughts:

First, once a nut backs off it probably will continue to do so - so it's worth replacing. They're readily available and cheap enough to replace all of them...especially since those seem to be Nyloc nuts (!)

The valve adjustment process is pretty easy and I've posted a FAQ on this site at the link below.

http://67-72chevytrucks.com/vboard/s...d.php?t=418725