Its shawn and that was a while a go. You can just drill and tap the spider.
What is the purpose of this mod? I'm not seeing that it would do anything other than remove two junctions.While you're making wires might as well do the big 3 mod. Wire from alt to drivers batt, positive and negative. Run the negative to the hold down bolt. Then block to frame. Be sure to fuse your positive wire.
Jax - typically when you hook up batteries in parallel you want to bring the positive and negative leads off opposite sides. Then when you charge the batteries they will charge more evenly. The mod that Shawn mentioned does something similar. It also gives the alternator a direct copper ground path back to the batteries.What is the purpose of this mod? I'm not seeing that it would do anything other than remove two junctions.