I usually buy Grade 5 stuff - I have some Grade 8 but I don't use it much. If the spacer has a separate hole for the clutch cylinder then I may have a grade 5 bolt that is long enough to get a good thread engagement into the spacer. They were too long to use in the upper transmission to bellhousing mounts as they bottomed out on the side of the bellhousing. It just looks different from the ARP bolts I used in the other positions
I'm still surprised Ford uses 7/16 bolts to secure the transmission instead of 1/2 inch. Maybe the 1/2 inch bolts GM used were some sort of engineering trade-off related to the aluminum transmission cases.
Patrick - your clutch rod doesn't look any longer than what I will end up with so I guess the spacer will work. I suspect I'm going to have to get in there with a dremel or cut off wheel and trim my clutch fork.
Thanks