I can't remember the exact specs but the series I 3800 rods are (i think) the same length as the 3.8L turbo buick rods. The series II 3800 has a 1" shorter deck height block therefore the rods themselves are about an inch shorter also. Sorry I can't give you specifics.
Yeah I know about the deck height difference and I know the length of the series one rods but the series-II is what I'm really after.
In Australia we have the supercharged 3800 motor fitted to rear wheel drive sedans so we are fairly lucky in that respect, however no-one seems to have specs on them.