with engines that didn't have marks, but which were already properly timed as yours should be, I lined up TDC exactly on the crank, then (with the old belt still in place and tensioned) made my own marks (either punch marks or filed lines) on the sprockets themselves opposite something obvious (like the top edge of the head or cam carrier) for future use or if the timing of anything slipped while installing the new belt.

It's also not a bad idea to count the teeth between the crank sprocket mark to the marks on the other sprockets you made( with the old belt in place), then using "White Out" typing correction fluid, paint the ends of the new timing belt teeth at the corresponding tooth counts with a white dot. Then, it's a simple matter of making sure the painted teeth are installed opposite the marked sprocket marks. Remember that as soon as you rotate the engine once, those paint moarks are no longer relevant.

Let us know how long the job takes (for future reference). I've never done a 960 belt.

Bob