Well, this reply is a bit late but here goes. A chip won't do you much good on your car. Going with Kleeman pulley upgrade is probably your best bet for the majors. Increases are generally close to 190 hp at the wheels with significant gains in torque as well.

There is a private individual who offers a kit (and installation) in CA that runs lower boost and it comes with cooler plugs, different fuel pressure reg. and dynos around 185 to the wheels. But your running lower boost and lower internal temps. Send me a PM or email if you're interested.

__________________
71 W111 3.5 coupe, European 4 speed
01 LX470
15 Yukon XL Denali
15 E63S Wagon