Thanks guys. One of the nice things about sliding back to the back set of holes (6 cyl holes) is that I was able to remain using the factory tranny cross member holes and that gave me a good idea od where the tranny and motor placement would be after the cab was sat on. I measured a parts truck that I have and looks like I have plenty of room. I was also able to slide the new A/C compressor in without any modifications. I am still in search of A/C parts but at least I have the compressor for the LS set up. I did have to drill an additional hole in the front cross member for the stud on the bottom of the CPP mounts but it was easy. Take into consideration that I made my own LS adapter plates that would mirror the holes of the ones that CPP sells but I also used the 4th hole on the block that they dont. After I had those made, they are supposed to be 3" forward mounts as per my reading and research (could be way wrong though, it is the internet!
) I then swapped sides of where I thought they were supposed be on and that gave me a 1" forward mount I believe, and gave me enough room to slide the compressor in from the front w/o any problems. Confusing enough?? haha!