440 Cam selection help

You can’t use the stamped steel rockers with a different length pushrod? What is the limit of the factory setup?
You "can" but you'll never get the lifter preload where it needs to be. As camshafts get "bigger" the need for optimum lifter preload becomes much more important. How much is this going to cost to build? And you're afraid of another $400? If there's anyone here who works on a budget (or lack thereof) it's me, but even I couldn't skimp on that. I'd find a way.