This hole here; is a 1/4 “ already there. What i did - so all factory holes could be used. I drilled it out to 1/2”.
This is driver side, but its basically the rear left hole. If u bolt it down to factory hole (i also bought longer bolts) and get measurement same from side of door trim. Went from the bottom and drilled / marked hole thru factory hole on front left. Drill it out to 1/2”, that gives u two holes.
Then used an ear i cut off for the third hole and welded it on.
This gives u 3 factory holes to use. I couldn’t use the front right on driver. Or front left on passenger, but i am going to bolt it in somehow.
Also, you will need to put 1” spacer in rear so seat doesn’t lean back. I am going to get rubber bushing spacers, but mock up i used some iron i had laying around.
See second pic for the spacers in rear.
See third pic , is passenger all bolted in and can see its ear inhad to weld on