I think of it like this: killing the 4G63 IMO is like Chevy ending the production on their small block all together, whether it be the 327(325 for all thos who want to get technical) or the 350. If you have a great platform that has already proved itself many many times, why take the risk with something new? Granted all of their R&D looks good on paper and should work "theoretically speaking," but only testing it will prove that it its in fact better. I'm sure they put many hours into testing the engine, but the aftermarket goes above and beyond anything the manufacturer does. I guess we'll just have to wait and see...