3D printing a seal tool for 2006 transfer case (rear seal on tranny for drive shaft). Dimensions?

I installed a transfer case seal (National 710689 - was super hard to find out which one at the three auto parts stores I went to) the other day. I 3D printed a tool to press the seal in and since I am going to pull the drive shaft again I am going to replace it again. I want to improve on the seal tool design. I will upload it here when done. So, I am kind of wondering on a few measurements (I don't have my shaft off the truck at this time). Are there threads (for an install bolt) in the center of the hole where the shaft splines go into the tranny? I figure there are so does anyone know what size bolt goes in there? I am designing tool #2 to include a hole so you don't have to tap the seal in with a hammer but can instead correctly press it in with a bolt. Also, my first tool was a good size but I am wondering if anyone had purchased a custom Tacoma seal pressing tool and could do some quick measurements on it. I don't know if such a thing is sold right now so I don't really know if you guys have them. Any help would be appreciated. Thanks!