Your problem is that if you line up the marks you made if you have turned the engine over you you will not know if you TDC compression stroke or TDC intake stroke. And the only way I can think of with the head off is to look at the fireing order turn the engine untill you figure out the math so to speak.Someone here should know where the other pistons are wnen no 1 is at TCD on compression stroke on a 2.6

Then reinstall you head put the cam sproket on its marks and roll a new chain in .You will be able now to check and double check the TDC indicator on the crank the marks on the cam sproket and cam tower TDC on compression stroke on no1 and check the opening and closing of the valve so that they are closed on no1 at TDC and the intake valve will start to open on the next cylinder in the fireing order as no 1 passes TDC and starts down on its fireing stroke.if anyone can make this clearer or if I have missed something I hope you can let us know...........

William Rogers........