i've done quite a few of deletes on good old c15s sdp.
you will get a great engine once deleted.
after installing the delete software, you will have to straight pipe it or gut the filter out.
also certain sensors need to be unplugged.
i recommend a delete with mild power upgrade, the guys I use and have a very good luck with are
https://truckecmtunes.com/
also i don't think you need to delete vva, since i hardly see any problems with them.