2015+ exhaust manifold vs older

Originally Posted by husam2012

Just letting who might be searching for this in the future; the 2015s do have a better exhaust manifold design. They actually don’t bolt up to the older engines because the studs are in a different location (the older heads don’t have 4 stud spots)
The pipes flow smoother and it’s more than likely that this causes the newer cars to dyno slightly higher.