How much more is it worth?

I have the same car in bad shape since I bought it in 1995, I would give $2K for the numbers matching block, been trying to find it since then and committed the VIN to memory 306021. I also have a 69 Dart GTS 383 4-speed and the block cracked in 1979, had it repaired at Indy Cylinder Head for $300 then, the cracks were about an inch south of where your cracks are, and it was fine after that. Your cracks are in a pretty strange place and MUCH worse than mine were though...