Backing braid on a 114 H Special

[Classtime]

I've got a 114H special with the aluminum frame. What do you recommend for backing 320 yds. of 65lb. braid? And how much room should I leave for the braid? It is loaded with 60lb. mono now and I want to use it for Rock Cod this week and then later to try again for Tuna.

[Gfish]

Before I finished reading the post, I was thinking 60lb mono. Double up the braid at the knot if using something like a uni.
What type of line do you prefer?
I've only ever got into the backing with a fish while fly fishing, so maybe someone else has a more experiential/professional opinion.

[Keta]

The braid should be your backing, I would fill the reel with 60/65 pound.

I splice 20' or so of the appropriate size Dacron on the end of the Spectra and attach it to the spool with a arbor or uni knot to prevent slipping.  I also use Flex wrap/Veterap on the spool.