No timing marks! 1995 Lumina

I bought a 1995 Lumina, with the X engine, V6 from a friend that said it was "making weird noises in the engine." He took it apart and couldn't figure out how to put it back together.

I am now attempting to install the timing belt, however there are no marks on the cam sprockets. I'm sure there is some way to know when the head is installed. The shop manual I have only says "If your cam does not have timing marks, be sure to mark them before removing the timing belt"

How can I know when the head is timed?

Damn that's crazy...everything I found said the same...there HAS to be assembly marks of some kind on the cams, flats turned a certain way or something...

I'll keep looking...

Rotate the crankshaft 360ºclockwise while looking at the front of the engine and align the crankshaft reference marks.
Make sure both right hand camshaft flats are down, then tighten both left hand (front bank) camshaft sprockets to 96 ft. lbs. (130 Nm).
Remove tool J 38613-A from the left hand (front bank) camshaft carrier.
Rotate the crankshaft 720ºclockwise while looking at the front of the engine to seat the timing belt and verify correct timing. Make sure both camshaft flat spots are up on one band and down on the opposing bank.
Install the camshaft carrier covers.
I was looking at this part...can you inferr from the relation after turning it over which way they face initially?