lets start again.
with the new battery in, can you get head lights?
or dash lights, or interior lights?
if the answer is no, then you need to back track your wiring into the car and see if that fusible link is actually burned out but looks good.
If that is truly good(using a multi meter), then start checking power into the car.
The amp meter is a good place to look and see if you have power on one side but not the other, then as said above, just bypass it. disconnect the battery, take the nuts off and move one set of wires to the other side and bolt it back up again. check again for power.

IF you do have head lights and dash lights but it won't start, see if you have power to the ballast resistor and then try to jump the starter relay with the key in the run position.

You could try that even if you don't have dash lights, but you won't have power to the ballast, but it will try to turn over the starter, and you would know it is just something stopping power from getting into the passenger compartment.