As others have said, you can use the really old style blocks.
If you're only using a few, you can get some individual inline fuse holders from amazon
http://www.amazon.com/MAXI-Fuse-Hold...ords=maxi+fuse
It's also possible to get 40 amp fuses (not auto resetting breaker) that are the blade size (smaller) fuses if you want.
http://www.mcmaster.com/#7460k39/=susd5r
You can use a board like this with them
http://www.amazon.com/Seachoice-ATO-...rds=fuse+block