Definitely change springs, the stockers will never hold up. Definitely upgrade the pushrods. Stock length should be okay, but you definitely want stronger ones. The added lift vs heavier spring loads will induce flex in the stockers. That's the last thing you need as the rpm's rise. I'd also add hardened valve spring retainer locks. It's cheap insurance. Also, expect to need computer mods. Sounds like CompCams Xtreme Energy XR265.