Re: 454 to 498 Build - how does this sound
I have 498 with RR 270s, but with a full point less compression. Your torque and hp estimates are low, mine made 621tq/624hp. I used a Chris Straub cam 242/254 on 107, my particular cam is for a heavy car, 3 speed auto and a tall gear so probably very different than what he would make for you with a stick and overdrive. I also specified that I wanted peak hp at a low 5700 rpm that in turn gave me a relatively narrow power band, but that is exactly what I requested.
If your cylinders are scratched 070 may not be enough, on mine the cylinders were still nice, it was a block I had taken to 060 and raced 2 seasons (20 years ago). If you have nice cylinders and just want to clean up have at it, but it may not clean up as well as your expecting.
Is your Header size a typo?