Bodi's right, here--I think you're causing yourself a bit more worry than you need to. with the cam sprocket marks even with the head, and the timing mark at T 1,4, you're right where you need to be. It doesn't matter if it's cylinder 1 or 4 that's at TDC, as the cam cannot in fact be 180 degrees out. The only mistake I think you can make (I know because I did it!) is to set the cam 90 degrees out of whack, which you do by bolting it up when the timing mark is at T 2,3. luckily, I figured this out before I did any damage by noticing that the valve clearances were all wrong and could not be set.
If you're at T 1,4 and the sprocket marks are aligned with the head, you're good to go. Please be sure to torque the cam sprocket bolts to spec. I used locktite on mine based on others' recommendations out of fear that they would back out and cause catastrophic damage... If you do, just be careful to wipe away any excess, as it hardens and and becomes brittle, and you don't want those pieces pinging around in the heads.
Once you bolt on the cam sprocket, turn the crank 360 degrees and make sure that the marks on the sprocket are still aligned. It's easy to be off one tooth.
when you put your cam cover back on, be sure to back the tappets all the way out and pull the rocker arms up out of the way (some use rubber bands for this), then torque the first 4 bolts under the breather cover down slowly and evenly. This should prevent you from bending any valves while installing the valve cover.
