The prior article, TC-335B, was about adding a crankcase vent filter without modifying any of the rare parts of the MGA Twin Cam engine (like drilling a hole in the rare Twin Cam oil filler cap). That modification is also very easily reversible to put it back to concours originality. The article before that, TC-335A, was about installing a vent in the engine timing cover, which does require drilling a couple of holes in the rare casting. This article has thoughts about a different and possibly less obvious way to do it if you don't mind drilling into the Twin Cam engine.

Mick Anderson in Australia suggests:
The fitting of a fresh air vent to the Twin Cam engine has two criteria. It should not be easily visible, and the air must be filtered. It should preferably be situated near the top of the engine for the best airflow. You need to drill and fit a small pipe to the rear of the inlet camshaft cover and have a rubber tube pass around to another pipe fitted to the backing plate of the rear air cleaner. It could be made practically invisible".

Proposed location for air vent from valve cover to air cleaner.

We so far have no takers on this one, but if anyone ever does it I would surely post the pictures. I am curious if it might interfere with access in that corner of the engine bay for tuning and maintenance.