Yes, they're for alignment. There are 6 flywheel bolts which sit between each stud and each group of 2 is locked in place with a typical sheet metal piece which you lift up with a screwdriver and kick a lip up onto the bolt head with a hammer. I measured one on a crank I have out there. It is 3/8 inch diameter, so I think any sort of 3/8" diameter rod would be able to be cut, end beveled a bit and driven or pressed in. Bigtime overkill on the length, but here's one at Home Depot: https://www.homedepot.com/p/3-8-in-x-36-in-Plain-Steel-Round-Rod-802447/204273959 A hacksaw, a vice and a common file to dress the edges a bit ought to put him in business again.

~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end