On another forum (earlycj5) I found that Land Rover V8 rocker arms are an exact match to the Dauntless V6 rocker arms. And on yet another forum (mgexp) I found that the rocker arms for from the 225 and 198 are also an exact match to the 215/300/340 rocker arms, the three of which have identical assemblies. If the Buick 225 had no change of its rocker assembly when bought out and changed into the Dauntless V6, that would mean Rover rocker arms and shafts are an exact swap into any of the five Buick engine mentioned above. I found the rocker arms, part numbers 602153 and 602154 for either side, available to buy from Eurospare, which the Jaguar community claims to be a good and reliable manufacturer. There are plenty of Rover V8 rocker shafts available on ebay. This is just some info I gathered and thought someone else can also find it useful. If I'm wrong about any of these definitely let me know, but from everything I read this seems to be correct.
I would say the rockers themselves are probably the same. I have heard that the stands that hold the rocker shaft is different from aluminum heads to cast iron heads. There are also cast iron versions of the rockers available, I got a set with an engine rebuild kit once.
I didn't know about the stand being different, that's a good note. Is it a material difference or design? I heard the replacement rocker arms aren't always as hard as OEM, but ones made by Rover are still up to spec, though about four times more expensive. Maybe a titanium nitride treatment could be used to help out the subpar arms. Do you remember the brand of the rebuild kit?
