Saying a solid roller isn't up to reliability tells me you're still in the past. They certainly ARE reliable for every single day usage. You may be reading, but you're not comprehending. I said a STREET SOLID ROLLER LOBE. There's the difference. A street solid roller LOBE is much less aggressive and will last as long as you want it to. Not my car. Not my money. That's cool. I hope your undercammed 512 works well.
As to the EFI, I don't think we're necessarily pointing the finger. We're more saying maybe TRY a carburetor as a temp diagnosis tool and "see what happens". I'm in total agreement with everyone that the camshaft AIN'T gonna give you what you're looking for. Even switching to a solid roller. Having said that, that's what that engine needs with the heads and cubes. I hope you find it, whatever it is. But remember this. As you throw all our recommendations back in our faces, you DID come here asking for help and advice. Good luck buddy. I hope you get it figured out.