This photo is of the end of the engine harness that goes to the starter. See that little white push point thing in the harness? That would push into some kind of hole to retain the wires back by the starter. So, where is the magical hole this is designed to snap into?
Look for a hole in the crossmember. (all my manuals are packed for moving and my cars are in temp storage, so I cannot get pics) But the wiring detail for the starter, should have a "line" showing where that anchor goes.
I had the same question a while back. Here is a link to an older post where I asked about it. I actually had to cut the black insert in the plastic block to fit it. I don't think it had one. See entry #13 https://www.v8buick.com/index.php?threads/70-gs-stage-1-new-wire-harness-wires-to-starter.308691/ And for more info, here is wiring it up, cause I didn't know https://www.v8buick.com/index.php?threads/red-wire-from-battery-where-does-it-go.355908/
That is the plastic battery cable block. It comes already attached to an nos cable. I reproduced this part in two pieces so it can be put on a repro battery cable and even reused.
Not sure if this is the exact same one, but Todd carries these ones: https://www.stage1restoration.com/product/battery-cable-insulator-assembly/
I saw that but I don't have a way to crimp the big cable eye on so I just bought the assembled cable from Todd. It's only money.
I made a couple runs of these. They're 3D printed and unfortunately they are kinda costly to make. I only have one left from the last run. I made this exact to the original specimen I had but just in two pieces so you don't have to remove the eyelet on the cable. The only issue is the original hole in the block is .425". The reproduction cables are slightly larger in diameter. So in order to install it with a lectric limited cable, I had to drill the hole slightly larger. Fred Hickey has the prototype block in his aquamist car which I drilled out
I got my wire in today. I don't know if it is the metal holder on that cable, my particular motor mounts, or the TA oil pan, but boy howdy is that mess a tight SOB. The motor mount has to be loose, in order for the cable mount to slide up between the oil pan edge and the side of the block. Ends up pinching the metal cable holder under the very edge of the motor mount.
Bill, I have one of Jason's 3D battery block thingys if you're interested. I ended up not needing it during my build. I'd just have to track it down in my stash.
I can't imagine installing one of these and the starter in an assembled vehicle. Sweet mother of god. Anyway, got it all in there, tucked the wire harness in and made a slot for the little retainer, then hooked up and bolted in the starter. Tomorrow I start the battle of getting it all aligned for that magical KLUNK when it all sets in place.
Yeah it was a PIA. I installed the wire while the motor was installed. Luckily I had no exhaust in the way. Don’t want to do that again.