The best 440 block is from the early 70's most likely from a motorhome. The number stamped on the side of the block is 4006630-440 that is the one with the thicker webs. after you get it torn down, look for core shift. then mag the block, if all of that is good, then proceed. the HP stamp is useless, only has to do with factory work shifts or some such crap, nothing to do with high performance. If you are just starting out, then I agree with Cab Burge, get a 400 block and build it, much better foundation for your performance build.