you could do 512 of swap....and 512 of fat.
it would mean little difference to the max swap of 256 applicable...
I believe...
you would gain no benefit ...since the system is meant to handle a max of 256

You may also run into issues due to the doubling of the size of the fat and swap....you wish to do....I cannot say for certain ..

but with an 8gb card....
if it were me...
I would max the fat and swap out to 256 ...
save the rest of the card space for program installation.

If you didn't do the entire walkthrough of mine...but just noticed it now...

I would suggest you do it from beginning to end ...
It is a piece of cake...
It is good practice...
and in the end is foolproof..
and if you screw up anywhere in the process ...you know it immediately and can easily redo it.

Look to my signature .
follow the links.