Testing for warped case? 4r100

I rebuilt my 4r100 (knew nothing of transmissions going in and after a month of slow progression and help from y’all and the transmission bench vids I got her back in and going

The truck is a 97 7.3, and its been nothing but issues

Finally racked up about a thousand miles (with help from a long weekend moving my girlfriend around Orlando, putting on the final 300 miles)

I noticed the pan was leaking after my last round of trips,

So I figured it’s the perfect time to for the first service

Dropped it and it looked pretty good in my opinion. Minimal ferrous fluid around the magnet, no big flakes

But the pans seen better days (I know someone tried rebuilding this at least once before me cause I found half of a transgo kit installed)

So I hit the pan with black permatex before throwing the gasket on

Chased the threads a little with a tap to clean em up, threw up the pan and Let it sit for a day

I just filled it and ran around the block and im now leaking from a seemingly different area of the pan,

Im curious how I would go about checking for any warp in my case and what y’all would do if you had my issue?

Im hoping a new pan solves this but planning for worst case scenario, I love this truck. But its absolutely not getting a new case lmao

Shifts fine knock on wood, so I hope to never open it again until I wreck it with 160 injectors whenever I can afford em 😅