ARP main studs for a windage tray

If I have to do that then my decision is made because the machine work is already done. I'm not signing up for that aggravation again. Months of waiting and TBH disappointing work when I finally did get my block back.

I guess if I can't find the impossible to find factory bolts then studs are my only alternative?

If you don't have the bolts, you might put out a wanted add. Someone probably has a set. I don't know if they are still made new.