Well, I just broke my 360 block. Terminal?

Since this is a very thin walled area to begin with, and we don't hear ever about cracks in this area, then I think it is safe to assume that there is little to no stress in this area normally, and will not be prone to cracks. If 'twer me, I'd:
- torque the cap in place and measure the bore dimension carefully
- braze it up a bit at a time and dress it down
- re-torque and re-measure carefully