Finally get to pretend I am one of the cool kids - Holley kit swap

I don't think that would work. The mount on the k-frame has a flange that captures the washer. The washer and flange on the mount are what actually keep the motor from lifting. Not sure there is room for the washer if I move the slot over. I could grind one side of the washer down to fit but that feels iffy as the washer would have to be oriented from then on when bolting the mount down.

I agree that I don't expect to ever go back to an LA.

One thing that hadn't occurred to me until this morning is I haven't even tried to twist the motor. It could be that it isn't square in the chassis and my 1/8" could all be because the header is pushing the back of the motor over. Something I now need to look into before I do anything. I might have to pull the motor and remove the header and see how it lands after that.

And yes, my brain is such that I can't just let go of this.
Someday, I need to educate myself on these pesky spool mounts. Could you just grind a little off one edge of the washer? Trying to visualize it