Final results:
- 3 out of 4 runners were cracked (one completely circumferential), re-welded and reinstalled
- one coil and/or its wiring was acting up, so it was replaced
I really want an all-new 321 stainless manifold made but the welder insists I should just run this one as-is for now. It's true that his last repair is the only runner that didn't crack... he knows how to do it right, so maybe it will last a bit. I just know most stainless steels aren't suitable for heat cycling like 321 is. So inevitably, it will fail eventually.
Drove all the way to the shop before I remembered I took the seats out for reupholstering. Can't drive it home with no seats. Sigh.