Re: 351C - 1970 Mustang Build
I think the stroker engine is key to making that kind of power easily.
You could get there without it, but it would tough on the street.
Do the 393 stroker kit, use either the 1970-71 Quench heads or the CHI aluminum pieces, and with a 3,000 stall and 3.91 + gears you should have a rocket.
Less Carb is better on cleveland I have found, I used a 650 double pumper on my 73 Coupe (12.2 sec 1/4 car). I tried a 750 Vacuum Secondary also and it just didn't perform nearly as well.