Just curious, I wonder if the SS has 150 in it? My GTP has seen 133 with not much room left in 6th gear. (CAI, Chipped, exhaust) My pops has a GP GXP that would be similar to the SS, I think they have the same engine, but I've never opened her up. She's a lot of fun to drive though. I think being an auto would keep the top speed down a bit... I dunno...