What George said, but I'll add that the first set is probably from '70. The '68-'69 rockers did not use plastic buttons to hold the rockers in place. As mentioned earlier they have springs between the rockers that push them against the bolt hole thingies (technical term :laugh: ).
Am doing battle with rocker arms at the moment too. :af: The aluminum ones were used 70-72 (partial year only) as at some point the steel ones were used. Supposedly there were no left or right on production steel arms (have several on hand with no LH or RH markings). Apparently the pushrod holes were larger on 72 heads so that they did not rub with the factory rocker arms. Replacement steel arms were LH and RH specific. Using factory steel arms with early heads (smaller pushrod holes) will result in the pushrods scuffing the head. Am planning to use later arms/lifters/pushrods on a 430 I am completing and will be checking the pushrod hole size (69 heads) and deciding what arms to use. Mark
Mark Is this only a problem with larger cams, or in any application? I've used steel rockers on 68 heads and 70 heads for years. Heven't noticed it to be a problem.
Steel arms are not the issue, it is whether they are labeled LH/RH or not. The factory used unidirectional arms with no side designation. Replacement arms are LH/RH specific. I have 2 sets of steel arms that don't indicate LH/RH on them and appear to be able to be used on either side. I read at one point that larger pushrod holes were needed on later heads to use the non-side specific arms. If the arms you are using have LH/RH on them, you should have no problem on early heads. My 70 motor has steel arms (with LH/RH on them) with no problem. Mark
I have factory 74 rocker arms bolted to 70 heads. Guess I better pull a valve cover and have a look-see
