If you look at the OE's, they'll stagger the drivers side shock rearward and the passengers side shock forward...it's supposed to help better control wheel hop on acceleration if I'm not mistaken, at least that was GM's reasoning when they changed their F-body application in the late 60's.
FWIW, I had the same situation on my EB when I put the new lift on it and I've played with the shock positions with no noticeable difference from the drivers seat. To be fair though, I'm just running the cheapie CAGE shocks, and while they're a good shock for what they cost ($38 IIRC), they are not a Bilstein. For the same reasons as RT above, I ended up with both shock in front of the axle as it maximized travel on my given setup.