OK, found your site again.
Did Keith put the breathers on or did you? Normally, the pentroofs come with filler caps, which do not have splash plates below for a simple reason...you pour
oil in through there and the caps seal it up. Towards the front, on the right hand side, you'll see a non-punched out hole on your manifold...that's where a breather can go rather than on the valve covers. It reaches the same crankcase area as the hole out back where your pcv valve is. If you don't want to put splash plates on the pentroofs, put caps in those holes and punch out the hole up front for a breather to compliment the pcv out back. Course, that's going to take more work than adding the splash plates in the valve covers.
You would need splash plates even if you ran hoses from fittings in the valve cover holes to a remote breather(s), which is what the separation (puke) tank actually is (caveman style).
The one concern is clearance within the pentroofs for splash plates. They don't have to run the length of the valve cover...a few inches out in both directions from the filler holes.