This documentary follows an old street racer and bootlegger, Mike Ondish. As he attempts to restore his 863 hp 1968 Shelby GT500 which has been sitting in his garage for 35 years. http://www.kickstarter.com/projects/66819244/demon-on-wheels-documentary-feature-in-production
428 FE, 863 RWHP on naphthalene/alcohol? I'm assuming that is SAE gross when it was measured back in the 60's. I'm guessing SAE net that would be well over 1000 BHP. I'm not doubting hi, but that is a bit over reach even with today's technology.
That's also a 1968 GT grill, fog lights, not GT500. Lower valance isn't shelby. The emblem they showed in the trailer looked like it was on right upperhand interior trim which is standard or GT, not shelby. Again, not doubting him, because if he is claiming to out run the police maybe some of these parts were switched out to conceal the car, but it looks like a little suspicious. Edit: Just read another article stating its a GT 500 KR.
Read that KR article too. All I've seen except one state it's a GT500. He might have switched parts out. In the trailer, he did say he repainted it alot to trick cops. As for the power, I'm with you. Sounds unbelieveable. I would think it would have some sort of forced induction system. There was only one shot of under the hood and all it had was dual 4 barrels.
He said that Ford & Shelby is backing him in another video too. I went to their website and couldn't find any information on that as well. I'd find it a bit more believable if atleast it was a 427, even then that could be a bit out of reach, especially for that era. There are people out there making that power on 427's, but they're also 500+ cid.