Yeah, it's nice to see that South Bend includes a plastic alignment tool with their clutch. If you are careful, and see that it wiggles "equally" in all directions out from centered, it does a fine job.
Easiest way to get a steel one is probably to get a bad input for an old big truck transmission. Lots of truck trannies used 1 - 3/8" x 10 inputs, but most had a 1" pilot bearing not 3/4" like Dodge. So, you will need to use an abrasive cut off to remove the gear, and then chuck it into a lathe and cut down the nose to . 749". Lots of work. . .