Crankshaft and Rod bearings for cast crank?

Hey guys. I’m shopping for my 77 slant I want to build, but I’m having trouble finding the parts I need. Particularly bearings. My main issue is that the only listing I’ve found that explicitly states that the bearings are for a cast crank only gives me options for an undersized crank, which I don’t have, nor do I particularly plan on having. Everything else either states that it’s for a forged crank, or doesn’t say anything at all and that makes me very nervous. I’ve tried looking up the part numbers but to no avail. Can you guys help me find a set of main and rod bearings for my cast crank slant?