I cannot really speak to the GTO ones, I thought about them too, but I went with what is proven on here. I have the same corvette ones. They tuck up pretty tight. I would say you might have trouble with the GTO ones. They look like they sit lower than the corvette ones, which means they would be hitting the frame rails. Once you actually start to mock up where the engine is going to sit, you will find that it is a balancing act between the powersteering pump hitting the powersteering box and the headers getting close to hovering above the frame rails. You want as much wiggle room with the manifolds as possible so that they are not dictating your powertrain and driveshaft angles.
