It wouldn't have been so bad if I had more than two and the one I broke wasn't the one that the ground wire attaches to. :banghead::banghead::banghead:
My JBWeld repair didn't hold up when I tried to put the nut back on, but fortunately I found a solution: Attachment 55933
There was enough of the bolt left to attach the ground wire and castle nut onto the stump of it. I poked holes in pieces of silicone tape and used them as a makeshift washer to keep it from leaking and it actually held up and didn't noticeably leak on the way to the shop. I told them to just go ahead and start taking the engine apart and see if they can figure out why it's only getting 75 psi. It'll probably cost me 10X more than the car is worth, but it's never left me stranded in 22 years, which is more than I can say for any other car I've owned and at least 50% of my immediate family...:headbang: