[blykins]

You're way overkill on everything, including horsepower. 800hp for a street car is just simply too dangerous IMO.

However, if you're set on that, I would invest in the block and the P51 heads, and skip the forced induction. You don't need it.

A longer stroke WILL NOT limit top end horsepower, but increases the horsepower along with the torque along the same curve, all while being able to use a milder camshaft compared to a smaller displacement.

A 4.5" bore with a 4.5" stroke will give you 573ci, and with that displacement, the right cam, and those heads, you'll get your 800hp and then some.

Don't take this the wrong way, but if you're planning on something like this, let a professional engine builder do it for you.

When you're listing a set of heads, and you're not sure if they fit a small block or a big block, building a 800hp race engine, may just be out of your realm of experience.

Have you ever driven anything with 800hp? 500hp?