Recently purchased an early Superformance myself which has a 460 based 514 SVO. I drove small blocks, strokers and big blocks before settling my search to big blocks only.
As we said previous, only issue is the cam/lifter possible issues with the 514 (mine were swapped out for roller units). Add the right valve covers, air cleaners and it looks completley proper in the engine bay as a 427 would.
460's have an excellent track record on the street, strip and race applications. Mine has 7k miles on it, doesn't burn a drop of
oil and goes like a raped ape from side to red line.
I had hesitations at first as well looking at a Cobra with a "truck motor" but now glad I went this direction. IMHO, you get all the advantages of the cubic inches without the draw backs of a stroker small block or FE motor design flaws.