Trans Crossmember Bolts/Washers/Nuts

I have a 73 Spool mount crossmember I have lost the hardware too, for my 72 install...

They are needed pretty badly. If they are a common size available in some store let me know, but I can't find one that fits right, they are either too skinny or too long, or the threads don't go far enough to be able to tighten the nut.