need help with oil filter attachment

I have a 340 I built. All is done just need to get the oil filter attached to the block. I have a 90deg adapter but I am running dougs headers. On the plate that goes on the block when you are not using the 90deg adapter there is a gap between the plate and block and gasket. Lit doesn't seat all the way it should. The gasket is thick but not thick enough. Any one have a way to make this work?

Thanks

Justin