Are they line bored to fit that one cylinder head or precision bored so that any fits any? I just had an interesting weekend that culminated in putting two helicoils into the timing chest and a further four into the cylinder head, all just to secure the cam cover. On no.3 exhaust camshaft cap the boss to secure the cam cover was broken into four parts (fortunately they'd stayed in the cam cover and not made a dive for the sump). Around three complete threads had survived right at the bottom of the boss, so I was able to cut an allen bolt down to exactly the right length and put some gasket cement behind the new rubber bolt seal to keep the oil in.

If the caps are precision bored than I'll replace the cap, but I don't really fancy replacing the cylinder head.

As the caps isn't sold as a single part, only together with a cylinder head
.......it seems like they are line bored.

I have replaced one, without any trouble. 

Maybe i was just Lucky. 

K-rider

Inge K. wrote:As the caps isn't sold as a single part, only together with a cylinder head
.......it seems like they are line bored.

I expected them to be line bored for accuracy, but I just thought I'd ask. Looks like I'm going to leave my 'temporary' repair in place; my guess as to why the cam cover has so many securing points (12!!) is to prevent it from heat warping. It's a very light casting.

Definitely line bored........

If you are using different caps my only suggestion is watch for and possibility of binding on the camshaft, camshaft will feel tight. An old hand told me that in such cases he would bolt up his cams so he could check they would turn freely by hand and only then put in the valve gear. Misalignment will increase turning resistance big time. Outcome would be broken camshaft....

I was thinking about it last night. It's not going to miss one bolt, so next time the cam cover comes off I'm just going to seal the bolt hole and not worry about it.

If you chose another replacement cap why would you not lap it in like we would with a white metal bearings In the old days?
Bearing blue would surely do it correctly. I mean it works with old pommy cranks why not our cam caps???

Some more options:

1. Get a cam cap and plasti gauge it along its entire surface or at least at the bottom, middle and top.
If the clearance is the same in all three locations you're good to go.
2. Take the valve cover bolt for the broken cam cap and install it in the cover with a self locking nut. Trim the bolt to fit. You may have to remove the remainder of the original threaded portion from the cam cap to clear the nut or use a skinny nut.
3. Have the broken cam cap welded and re-threaded.

The cam cover doesn't flex enough to make it worth the effort. Now, if it was two cam caps side-by-side, that would be a different matter.