I have no idea on the v6 I'm sure someone else can chime in on that. If you have the factory service manual that would tell you. I believe the oil pump has its own timing marks for itself though.

 

Okay, first, the V6 is a non-interference engine. Which means if you break the timing belt the piston won't hit a valve. Or you can crank the engine with the cam off time and not damage the piston (you could damage something else, but not the most obvious things.)

The harmonic balancer has an annular rubber ring that separates the outside (where the belts ride and the timing mark is) from the inside (which attaches to the crank). It turns out that rubber can fail, and some time before the whole thing comes apart the outside of the balancer can turn. Which means the timing mark is no longer at TDC!

If that happened, you'll never be able to set the ignition timing (plus the balancer will come apart soon -- and at the worst possible time). You might be able to visually inspect it, but I would just bite the bullet and test it. Put a wrench on crank bolt and a plastic straw down #1 spark plug hole, so you can feel the top of the piston (you can use a wooden chop stick, but don't use a metal screwdriver). Rock the crank back and forth to confirm the piston is at TDC when the mark on the pulley lines up with the degree marks.