If you think the kinetix is a waste on n/a why bother with the Cosworth? Do a search on my350 & you will see how poor it performs on a N/A Z
My headers took around 10hours to install, absolute bitch of a job & not something that will be done again. There are gains from them but unless you can get a good set for a silly price then don't bother.
Also, the Kinetix stuff seems OK for stock engines. I ran the V4 for a while & Anders is running the SSV with AFAIK no issue