took the rocker box off this afternoon, all is as it should be pushrods located correct both ends.
Compared the box with the one I took off, no difference in the height of it as far as I can see, or the position of the rocker shafts although not too scientific a measure.
However the casting number under the box is interesting the one on now 67- 208 but the original one looks like 67-308 very difficult to be certain with cast numbers tho.
anyway as I'm this far I have the head off and will lift the barrels tomorrow and look at the camshaft, doubt if I'll find anything (hopes) but nice to have some confirmation