Can I ask where you got your rockers from?

 

No problem. Roverparts.com (aka Atlantic British).

I stuck with aluminum (steel cost more). Item 602153 (right hand), 602154 (left hand), 611659L rocker shaft. That was 4 years ago. Looks like AutohausAZ has them for less than I paid. Each side gets both kinds of rockers, right and left refers to the position of the bearing pads. You'll see they are offset differently when you look closely.

 

But oddly, AB offers the whole rocker assembly (#611660) with no indication as to which side it's for.

 

i had my cleaned by the machine shop and stupidly lost track of which side was which… I’m not sure it matters…

 

To get the oil supply holes to line up, one rocker assembly has the notch towards the front, and the other towards the rear.

It isn't the assemblies that differ, it is the individual rocker arms. One type has the bearing pad towards the right, and the other towards the left. Both types are installed on both assemblies, one L and one R on each cylinder.

 

There is no L/R when it comes to Rocker Arm Assemblies. Yes to individual rocker arms, but when assembled you can mount them on bank 1/2.

 

Eventually got to the bottom of all of this. My issue ended up being 2 brand new, but bad lifters. Also, some pushrods and rockers needed to be replaced ultimately.

 

Just chiming in that my 3.9 developed a worrisome tick and it also turned out to be a loose cup on one rocker arm. Just enough to allow it to spin in the arm, almost missed it even though I was specifically looking for loose cups, and surprised that it was enough to make that noise. But cleaned an old arm with good cup and installed and engine is quiet! This was on a pretty new shaft assembly from britpart which has the cups stamped into the arms in a pretty crude way...