I used Mile Lewis for the rotating assembly in my 496, gosh probably 10 years ago, and everything was absolutely top notch. huge thumbs-up for Lewis Racing Engines.
FWIW, I'm having a hard time believing the OP scored a virgin, standard bore 454 block for $50.
Not really. A couple of years ago I stopped by my friends house on the way to a Wednesday night race. He does a lot of scrap, in front of his garage was a standard bore 454 block that spun a rod bearing. He was about to load it with some other metal and bring it to a recycling center. I offered to buy him lunch at a later date for the block, he agreed and put it in the bed of my truck with a fork lift. Within an hour of arriving at the track two people I knew tracked me down and asked about the block. I sold it to one of them for $100 on the spot. The guy I got it from said he wonít touch something that is potential scrap more than three times, with the third being itís trip to the recycler. In his mind, any more than that and itís not worth the time to load and unload something as well as spend the time dealing with potential buyers on the phone or Internet, then in person.