From the info page you provided, it would appear that the intake timing is the same for the 18/19 and for the 26/27 cams.

The duration of those cams, combined with the late intake timing, may simply be too much for the smaller displacement 3.8L. Both fuel consumption and performance are likely to take a hit.

The 08/09 cams are much closer to what was used in the 3.8L in the rest of the world (ROTW), but would benefit from being advanced by 6deg. (crankshaft). When advanced, the 08/09 set would match the 70/71 set.

Ignition timing, as always, benefits from being adjusted to local conditions and fuel choice.