How come you're using srt8 manifolds ? The port match on the 5.7 and 6.1 will/are different. Just curious. The front end looks good. I got my hands on an alterk this past weekend, but my buddy wasn't going to let go, so I had to, damn bad luck.
The ports are slightly bigger, should not be an issue. Almost all the header manufactures sell their pipes to fit both engines. Nice try on the Alter K.