Hi Joe,
What I am talking about, is based on the EMC engines that both Kaase and Blair built for that competition and based on a ~460 CI max size, as that is what the OP is talking about, with his 428.
I believe Blair's almost 600 HP out of a little less than 400 CI, beat all comers, including the BBC heads that Ford copied for the 429/460, 385. Is that correct?
I'm talking with a head porter, right now that tells me, that even though the stock FE's ex port is bad, the 460's is worse and flows not much more than a SBF. It was hard to believe, with the 460's much larger ex valve but, that's what his flow bench showed.
To my other point, what do you do, with a 545/557 engine, on the street, rather than have bragging rights for the biggest engine? That power can't be used for more than about 3 seconds and there, the car with the best traction will win, with street tires. Not easy to get a street tire to hook up in a 3500 lb car with over 700 HP. I would bet on a SBF 427 Cobra for that. It might be close but, that would be my bet.
Those are just my opinions but, HP/weight, will win in at least the first 2/3 to 3/4 of the 1/4 mi and it takes a hell of a lot of HP to over come that.
A drag racing example:
550 hp 332 in a 2200 lb Falcon = 4 lb per HP
800 HP 557 in a 3500 lb Mustang or Fairlane = 4.375 lb per hp.
The Mustang may come on stronger at the end but, which will win?
Frontal area comes in to play, on the top end, too. The Falcon has less of it.
The 306 that I'm building at ~500 hp, setting in a 1300 lb car gives 2.6 lb per hp, how would the 800 hp/3500 lb car, do against that?
My biggest point is, I guess, is what good is that 800 hp on the street, even if you can get past the next gas pump?