Surprised the GOUT-synced Castilian audio is noticeably off in 4k83–the lip sync on that dub isn’t super-tight to begin with. Have you tried just using the unmodified GOUT track with 4K83? i.e. don’t try to fix something unless you’re sure it’s broken.

Otherwise, you just open the audio in Audition (that’s what I use), and insert .083 seconds at the right timestamp (not at a computer where I can look this up, but it’s around 1h40m, during the rebel fleet shot right after Luke’s last Dagobah scene). To prevent a gap, you’d need to stretch the audio over the gap, and that’s a little more complicated. Copy a chunk of audio overlapping the gap (before you make it), THEN insert the gap, paste the audio into a temp file, stretch-maintaining-pitch so it’s .083 seconds longer, then copy and re-paste over the stretched audio back onto the same timestamp with 50ms crossfades.

Longer term, I think creating a GOUT-synced version of the 4k83 video would solve a lot of problems. If nobody takes up that mantle for a while, I just may.