318 with a 4.00 stroke crank

I have heard of a few members building this motor. I was thinking last night, What the bob weight would be on this combo. It has to be light, lighter than the 340 and 360's right? If you are using good quality lightened Pistons and Rods. These things should fly... I would love to hear what some combos are that have been built and H.P. and Torque #'s if anyone has run one on a Dyno. I have the perfect 318 shortblock for a build like this. Also what are the cubic inches you are getting, Is it 392? And what are the current piston bores availible?

Thanks Alot Guys.
T.J.