How to seal help

The day warmed up to about 50 F today so I went out to install my dual's and intake manifolds :happy10:
After getting all my parts outside I set all my washers and seen that there is a problem :tongue9:
The split exhaust manifolds want to move away from the cupped washers and not tighten up to the gasket #-o

And I am sure that they will not stay in place.

Any thoughts on this, The intake is tight and the exhaust I can wiggle a little