I love these comments. I have a stock block that runs mid 8's at over 160 in a 3400 pound street car. It has made as much as 1200 at the wheels but its not very tested, it only has 120 runs on it and about 1500 street miles. Then there is my nitrous car that's 372" (14:1 compression) that makes 645 on the motor (flywheel) and I hit it with another 275 of nitrous. But again its not very tried, it only has 300 passes on it and is 17 years old. I must have missed the memo on blocks breaking.
If you can find a set of W5's I highly recommend them. I have been running them for years and will support an easy 700hp. You want the later blue pipe plug version. I think mine flowed 340 cfm intake side and they weren't ported all the way. We need to leave some meat for strength incase of backfires. I also recommend calling IMM engines because he is very knowledgeable about the small Mopar stuff. I have used him for years and his porting is excellent (not to mention his machine work) and he is honest and not super expensive.