This is the harness out of my Camaro and I found it has two wires going into one fusible link then going to a connector with a single wire attached. And then the 4th wire is by itself with a fusible link. I am saving this harness in case my pcm swap goes haywire on me. The harness I bought had all the wires by themselves with fusible links attached. (It was in rough shape) Is it necessary to attach the wires the way they are in the picture or can I keep them separate and attach them to the distribution block?

 

Individual wires works theoretically on paper as long as fusible links are sized right. In the real world though you want to limit the number of ring terminals attached to any one location. No more than two ring terminals attached to a stud, maybe three at most. The stock wires may have been routed from multiple locations originally.

 

I have one of those 4 post distribution (3/8” bolts) blocks that I’m using from amazon. Fusible links are 14 gauge about 5 inches long.

 

A 14 ga FL is appropriate for a 10 ga wire. All that they protect, is the wire itself. As long as that's the size that the wires are, and as long as the stud on the terminal block is long enough to support the batt cable or whatever else is feeding it and the 4 rings as well, then you can hook them up that way. Put the heaviest terminal on top right under the nut.