Matt,
I don't think you want to replace the fusible link with a big fuse. Most fuses of the mega stereo high amperage type would blow too fast. The other thing is a fusible link is a well sealed, minimum connection device. Most fuses (fuse holders) will corrode and give issues before the usual life of the vehicle is over.

My understanding of the fusible link is that it acts like a very very slow-blow fuse in its characteristics. It can withstand a backyard (and licenced) mechanic Sparky shorting the odd wire and live through it. They are protection against a very high prolonged catastrophic short such as would happen in crash.

I tried looking up the electrical specs one time, but did not find anything. They only seem to be sold on wire gauge size.