I have to agree, that you're probably looking at an aftermarket block for those kind of numbers. You'd be gambling with a stock block on whether or not it'll survive. The two grand pricetag that was mentioned above is the price for an unfinished block, and it'll still need finishing in order to be used (bore/hone cylinders, align hone mains, possibly deck the block, install cam bearings and freeze plugs, clearance cylinders for rod clearance, etc).
I have to agree, that you're probably looking at an aftermarket block for those kind of numbers. You'd be gambling with a stock block on whether or not it'll survive.
Rick is finishing up my Dart 347. I was originally thinking of staying with the prodution block also, but after realizing that the cost of another cracked block would eat up any savings by not going with an after market block. So I decided to go with the Dart. My motor will start out life NA, but as soon as I can afford it I want to put whatever amount of boost that can safely run on 93 octane to it.
DSS is a joke 1/2 the stuff that comes out of there breaks. Do some research on them and you will see... Anyways people say stock blocks are good for around 500 rwhp so it sounds like it would be a better idea to go aftermarket block for you. Though Ive been on the turboforums lately and have seen alot of stock block 9 second turbo cars putting down some serious numbers and running for years. Check out world man-o-war short blocks. They are offered in 302 and 351 based, strokers avalible with good internals and pricing. They were about $4500 but now like everything else the price has gone up, too I believe $5000 give or take. Or talk to Rick and see what he can do for you.