I'll take Robbies idea one step father. Get a dart block, and a good forged 408+ stroker. Since you have to use the GT40 lower with the flowzilla manifold, you are in luck as you can probably get away with running the 351 GT40 lower. As Robbie said it WILL need ported, and more than likely it will need ported enough that welding of the runners (in particular the #1 and #5 intake runner due to their inherent dog leg design where they go around the distributor) will be required. The stock 302 block WILL NOT WORK, its too thin of a casting and will literlally split down the center of the lifter valley with high HP. Figure around $6000+ just for the shortblock and rotating assembly. You'll also need a COMPLETELY new fuel system which included pump(s), fuel lines, rails, and more than likely a sumped tank... figure around $1000-$1500 for that, you'll need LARGE injectors and if you can not get away with with 60lb/hr you will need to get a driver as all injectors to the best of my knowledge above 60lbs are low impedence and will not work with the stock ECU. These are just a few of the things you will run into when trying for 700rwhp.