I recently did some work on my front diff mount and strap and here are my findings from the project. It was my first time messing around with these parts.
Here is a pic of the old mount and original hardware. I'm replacing the mount because the rubber is soft and squishy. The original hardware holding the mount to the diff is hard to remove because the mount itself is partially in the way. It's much easier with the whole diff out of the car, but if you're trying to replace the mount without dropping the diff it's a pain in in the butt. I think you're supposed to remove the hardware using an open end wrench on the bottom and a box end up in the trans tunnel hump on the nut up top:
I decided that since my original mount was already 75% split and squishy, that I would just split it the rest of the way and pull the bottom part of the mount off which allowed me to use a standard socket on the bolt head. In other words, I finished the destruction of my old mount to get to make getting to the hardware easier. Here's my old split squishy mount:
When it came time to put my new mount in, I changed the mounting hardware scheme to socket head cap screws instead of the original hex head bolts. I don't know if this is old hat or not, but my custom hardware looks like this. Socket head cap screws on the left in this pic:
So what's the big deal about using SHCS there instead of hex head bolts? The SHCS allowed me to use a hex driver on my ratchet like this:
And tighten the bolts from the bottom like this. The hex driver clears the bottom plate on the mount so you don't have to deal with the original hardware anymore. If I ever have to mess with this thing in the future, it will be much easier to R&R. Box end wrench braced against the diff body to hold the nut on top and hex drive to tighten from the bottom, I found this much easier to work with than the original hardware scheme:
I used 1/2-13 x 4 inch long socket headed cap screws. You could also use M12 SHCS if you can't deal with the English hardware on the Metric car, but since the English stuff is so much more prevalent and cheaper for me, I used Engilsh. I used the black oxide hardware below to test fit, but for my final install, I bought some new zinc plated hardware for corrosion protection. This pic was before I had the zinc plated parts bolts on hand: