Even though I sit on that codes design committee I must admit I have never seen a SIF for a trunnion let alone a pair of trunnions of undefined size, and thickness as well as an undefined header size.
My sarcasm notwithstanding you are all on your own... but I can tell you that if any part of one trunnion is within the (R/t)^0.5 distance they will have overlapping stress fields and are definitely undefined by the code.
Try some FEA instead of relying on a simplified program and a simplified code!
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Best Regards,
John C. Luf