Putting both marks facing up, the left one is TDC and right one is for timing advace. That's only to show you which mark is which, if you truly know how to find TDC, then locate #1 there and you will see that the left mark of the pair does indeed line up with a small bump on the oil pan casting. I made the pin and cam tool for a total cost of like $5. The VCT exhaust cam is indeed spring loaded. That is to assist hydraulics in bringing it back advanced as engine rotation works against it in that direction. Main function is however hydraulic, with 'mechanical spring assist in one direction' let's say. Your statement about having tool in place and engine at TDC is correct, on VCT you go through one extra step by making sure the exhaust cam is rotated as far advanced as it will go till hits internal stop, THEN tool must fit in it. There are flats cast into cam to allow putting a wrench on it to rotate it toward the FRONT of car to get it in proper place. If exhaust sprocket loosened and that rotation step not taken during tool check there is possibility of mis-indexing, and resulting DTCs from not having proper VCT timing. That's why I say there is no need to loosen exhaust cam sprocket, that saves losing that critical positioning. If you just roll belt around 2-3 times in normal rotation direction, you will not have any slack troubles from not loosening the sprocket. Any slack will run out to the tensioner side and tensioner should be rechecked for possible readjust if not in range. Belt should be hand rolled around and cam tool slipped back in again to recheck your work anyway, many don't and cry about belt loose this or that. Most of it failure to do the work right. Whatever you do, do NOT turn belt backward at any time. I've now gotten to where I don't even loosen either cam sprocket and have no trouble getting tool to fit right and motor runs fine. Ford manual procedure unnecessarily complicates things to me, if cam/sprocket not loosened and tool does not fit, then slack not run out right to backside or belt is crap and does not repeat tooth to tooth distance, meaning get rid of it.