Dunno about that, but the rule of thumb I use on pretty much any engine is this:
1) Line up the marks and install the chain.
2) Check mark alignment.
3) Turn the crankshaft exactly two full turns.
4) Re-check mark alignment.
If you want to worry about it; then repeat, going exactly ten full turns for Step 3. Re-check
That's how I did it before on my 4.0, and how I learned to do it 'way back when (around the time Moses was still a mess cook, I think...)
The gearing between the cam and crank is 2:1 - for every two times the crank turns, the cam goes around once. Thus, the even numbers.
If you stop after an odd number of full crankshaft turns, you'll find the timing mark on the cam gear at the top, rather than at the bottom. Use a straightedge when you check marks - you should find the cam mark, crank mark, camshaft centreline, and crankshaft centreline all on the same line if you've done everything right (whether the cam spot is at the top or the bottom.)