I see now.
You can plan on a just a little bit over 3", so you'll be moving the 205 forward by 1/4 to 5/16".
When we built the welded adapters, the parts were machined, it was all welded together, then the weldment was machined to make sure it was all square. That's why we don't do that anymore, too many steps to make sure it's right.