You got that right on the stainless. There are stainless bolts that measure up but you don't even want to know what the price is. Especially if they are big and certified and made in the U.S.A..

As for gr 8. You can't use enough of them. Everthing possible on my car is grade 8.

Last year I found that White Pine is stronger than grade 8 bolts, chrome moly high end rod ends, and 4130 chassis suspension mounts. I made full contact with the tree at 60+ in the sand buggy and removed the left front suspension entirely. No bolts broke, no welds cracked or failed but the 2 of the 4 5/8 rod ends did bust right off leaving the bolts and tabs on the frame. The other 2 rod ends ripped thru the tabs like a sawzall.

I also got to test in real time a 5 point racing harness mounted with gr 8 bolts. The harness survived totally intact like nothing happened. My aging body however took a couple days for the bruises to blossom to full color then another few days to go away. I only remember getting hit like that once back in my tight end days. It just served to remind me that the tighter the belts are the better. Good thing they were tight or I might have found out what impact with the steering wheel feels like.