I had a Magnusun blower which was a TRD part on my 1999 Tacoma 3.4l. Full warranty, Toyota never had a probalem- probably because TRD offered it. FYI- he guy who ones the truck now still says it runs great and no issue with well over 150k on it.
http://www.magnacharger.com/t-Will-i...-warranty.aspx
Now there is something to be said for these motors such as the Hellcat which are engineered form new with the blower in mind. Many turbo motors have the oil squirters to cool the wrist pins- probably SC ones too and I'm sure a few performance N/A motors do, sodium filled exhaust valves tend to be reserved for forced induction, better cooling and a beefed up crank snout too. Many motors live a long life without these items, but there is peace-of-mind when engineered as new.
I'm not one to worry much about voiding warranty. I've always had success talking through differences in perspective and related failures.