Does replacing rocker arms stop the ticking?

[skuhler]

I'm in the middle of replacing the valve cover, with one on order with a new gasket, and I noticed that a couple of the rocker arms are looser than the others.  The ones that are loose actually slide back and forth under the bridged pivots, while the others are nice and tight.  My question is, would this be the cause of the ticking noise I hear at random intervals while at idle?  The noise is definitely coming from the valve cover.  Would it help to get some "tight" ones from a head at the junk yard?  I expect that any replacements should be done in pairs using the rocker arms and bridges from the other head, not a mix and match, but does it make any difference?

[carnuck]

The cam will be pushing on some of the pushrods at any given time so they won't be loose. If you're lucky only the rockers are worn, but usually it is the lifters and cam worn too. Extra pressure from new rockers can wipe out what's left of the lobes. What I used to do was turn the motor to TDC of each cylinder and see how much slop there is in the rockers. Then take the rocker pair off and grind down the aluminum pivot equally until the slop is barely gone. Keep in mind that you grind only 1/2 the amount of slop clearance (if you measure the gap at the tip of the rocker to the valve stem with feeler gauges) because it's divided side to side. My first time I ground too much off and the valve hung open.

The other possible bad effect, even with new rockers, is that the extra distance the valves now open may be caked with carbon and cause a sticky valve.

[skuhler]

I wondered about that.  So the ones from the junk yard will be worn differently than the ones on my motor, so there's no guarantee that it won't make it even worse.  New ones come with their own set of problems due to the cams and lifters, maybe I should just leave it alone and get used to the ticking!  Your TDC trick would work great, just takes a little time and labor. 

[carnuck]

Having been a broke college student (when I got my welding, mechanics and partsman cert) single dad, I had to cut corners where I could.

[skuhler]

I understand!  My dad grew up in the Depression and always said, "use it up, wear it out, make it do, or do without!"
He was a farmer all his life and taught me that as machines age, parts wear together and create kind of a rhythm as they work.  When you start replacing old parts with new ones, that rhythm is upset and the new parts will sometimes cause the old ones that were working fine, to fail.  That's why your TDC solution will work better, the only thing you're changing is the wear points at one location, not several.