Problem solved! PALM FACE
When I replaced the starter, I loosened the Positive terminals battery clamp- realized I was loosening the wrong nut and went ahead and took off the one from the actual battery post.
When I put everything back together… of course..
I didn’t tighten the clamp back up..
so I had a nice tight connection around my post.. but the cable that bolts into the clamp was loose.
there was some corrosion under it as well.. but not enough to make it fail, I don’t think so at least.
I scraped it clean, tightened everything back up.
Opened the fuse box and gave all my fuses a push for good measure.
Engine Fired right up.