My guess is that you won't be able to get them without the 2 holes on the top. They are there for the "polution gear" minded person - unlike myself!
You say you have them plugged with "switches"..........if you just put some nice brass or anodized blue/red aluminium plugs in it would look OK.
The other option is to fit an old falcon chrome housing with no 90* neck, just straight up. You'll have to buy the matching hose. Just check the lengths of the hose though, I think the XD/E radiators are wider & therefore the radiator inlet is further away.
So, instead of heading SW to the inlet, old falcons are more SSW