A guy sitting on a mound of junk blocks would not know where Kirk is located. Might it be a secret? Some of the "subtle differences" will make Model A block as mock up, less useful. Oil pan and candidate trans may be a problem for an A block. Where B running gear is used, kind of frame makes a difference. However, where Kirk may already knows all this, we're left to sort it out for no use. Good Luck: Fred A