Tried again this afternoon to put the rocker box on ..
just not enough room to get it in place with out hitting the pushrods.
The box will need to push the rods around before it's in position.
Could it be this non a 10 frame ?
I will try again tomorrow but this time remove an adjusting cover stud to see if I can get another half inch clearance.
I don't know if this applies to you; on the Plunger one of the rocker cover studs has flats so it can be removed to facilitate removal and replacement of the rocker box. I don't think it's possible without removing that stud.
Once you have the rocker box on the engine:
It seems that unless you have very long, slim and flexible fingers, (or you have a large pet spider, which seems possible in the Antipodes) you will struggle with rocker box refitting. Some say, it gets easier with practice. All I know is, he's called the Frig!
Just don't bolt it down hard until you are sure they are all in their cups.