I'm gonna throw one more thing out here, not necessarily directed at Don, but all my RRR friends. I hope I'm not just stating the obvious but - If you can find a "modern" block to begin your build with, you will be way ahead of the curve. At least as far as SBC or SBF, a roller cam block generally gets you all the good stuff right off the bat. Cylinders that are round with less wear because instead of a carb with a choke washing cylinders they were FI. Better connecting rods and pistons that probably will have less mileage, easy one piece rear main seal and the kicker, a hydraulic roller cam set up. Yeah, the cams are a little more money but, no special oil and they make great power. At my favorite speed shop the owner will try his BEST to talk you out of a hydraulic flat tappet or solid flat tappet cam because he has seen this very same issue play out time and time again.