No offence BigBird but computer generated HP/Torque numbers mean no more to me than other claims made by people who don't have REAL dyno sheet.

Building a SBC to make those HP numbers is possible, making it live past one dyno run is expensive. First you need to decide what size engine you want to build. Check some of the previous posts and you'll see a several discussions on the heating issues associated with the 400 SBC and the reasons. If you choose to build a 400 cooling will likely be an issue especially in the enviornment it's going to be living in. Although you would give up CIs a 350 or a 383 stroker may be the way to go.

Block: Either go with a new block or one than can be cleaned up with a minimal overbore (.020 for a 400, .030 for a 350).

You'll need 4 bolt mains and although you could start with a 4BM block, I think I would go with aftermarket splayed 4 Bolt main caps.

Wether you go with a new or used block have it sonic checked, and all the work done by a competent machine shop.


Rotating assembly:

A steel crank will be a must and again I would go new (if your doing a 400 or 383, the factory did not make any steel cranks for the 400 so you'll have to go aftermarket). If you find a used crank discard it if it does not clean up at .010/.010.

Stay away from aluminum rods. Buy the best set of steel rods you can find. At a minimum you should have them magnifluxed, big ends checked (even if new), the rods shot peened and the beams polished.

Pistons should be forged. Even though the hypereutectic are stronger than cast and lighter than forged, they are more brittle and less able to handle the abuse of the HP you want to make.

Have everything balanced. A good starting point when choosing a shop is to ask them what tolerance they hold their balancing to. If they say anything more than plus/minus 1/2 gram find a new shop.

Use the best fasteners you can find, and use studs for the mains and heads.

Congratulations you have just built a VERY expensive shortblock. (to get an idea, pick up a PAW/Summit/Jegs catalog).

The top end of the engine; cam (I would definatly go a full roller set up), heads, induction, exhaust etc you'll need to define your paramaters a little better. Are you going normally asperated, supercharged,turboed,NOS? You really need to know the RPM range your really going to try to make the engine live in (generally with high HP numbers you want will only occure in a VERY limited RPM range). For that you need to define what your vehicle is going to do, weight, gear ratios etc.