Cheapstreet, I will answer a few of your questions. I am currently running a set of herberts in my 408. I had to grind my block to get the link bar passed the lifter valley. For stock heads I would run the comp 917 springs and install them at 1.750. Can't tell you what valve but they were from hughes engines. This should give you around 240 lbs of seat pressure. I ran the herbert .604/.603 roller in my 340 and it would go to 7400 but I shifted it at 6800. It did run about a tenth quicker if I shifted it at 7400. This was in my 340 with ported 587's from hughes.