Trying to figure out if I have two oil leaks or an oil and transmission leak on my 73 Duster 318

For the time being, use the piggy back one. Thread the big part in with a good gasket and leave it there (the more you work whats left of threads in the pan, the more likely they will fail). Use the small pipe thread plug for the repetitive draining with a little teflon tape wrapped around the threads (in the right direction of course). This will get you by until you get the pan repaired.

I wouldn't use JB on the big part. The gasket should suffice.

Another type of fix..........Find a metric plug SLIGHTLY larger than your stripped out pan. Drill and tap to this size.......Will save you a pan replacement. I did this on my '87 Ram and it's still there today. Don't go too big or you'll ruin the thick metal inside the pan that takes the threads.

Good Luck
Thanks for the info!

The new piggyback is a double oversized bolt where the old one I took off was only single oversized. Any idea if these oversized bolts are supposed to be self tapping or would I need to drill and tap anyways just to get this slightly larger piggyback to fit?