hope this helps,

I'm not sure about the newer 350's but on the older ones the valve lash adjustment is not a tighten till it's tight method. on the SBC and 4.3 V6 the lifter needs to be in the proper position on the cam shaft ( base of the lobe ).


There are several places on the net to find the information, you need to know if you are at the firing position for #1 or #6 when the TDC marker is at ZERO on the balancer/pulley

SBC Order
http://www.thedirtforum.com/chevyvalves.htm