If I remember right the inside of the blockoff plate has about a 1/2"-3/4" hole plus 2 mounting holes. I think mine also has an o ring to seal around the inner hole. It's a very simple piece and if you know a machinest they should be able to make you one but I doubt it would save you any money.Originally posted by Trevor
Can someone show me some pics of the block offs front and back. Are they just flat on the back or are they hollow?