It was bound to happen. Basically putting in another 7.3L running in tandem with the original (doubling the power) isn't really transmission friendly.
A couple Benjamins for a kit and I'll be on my way again. I wonder if I should replace the flexplate while I'm there?
I'll continue to drive it though. I would hate to walk as far as that transmission will still go with normal usage.
When it starts having a problem in this power level, I'll yank it and re-clutch it.