Looking at an E-bay photo there are 2 long bolts and 7 short bolts.
Both lengths look to be the same diameter and thread pitch.
My guess is 5/16-18, but may be 3/8-16?
If 5/16 bolts:
Short bolts look to be about 5/8" long.
Long bolts look to be about 1" long.
![2022-10-17_193448.jpg 2022-10-17_193448.jpg](https://classicbroncos.com/forums/data/attachments/890/890058-5a605dedfda9601c5c06b8c613b7df7d.jpg)