IMO, I suggest that you read the rules for pure stock racing, these guys get impressive results and they have to use factory carb, intake, cylinder heads and the cam has to have the factory lift but there is leeway on the duration that you can run,there's articles on what tricks they use to get the power that they do.I don't remember the guy's name but his 1973 340 duster has ran a 13.98 et at just under 99 mph. Another book for great information is mopars engine builder's manual, it's like 650 pages and covers everything from the slant 6 to the 426 hemi. As far as my experience, I may not have as much as some people on here but I do have some knowledge and as usual no body agrees with me on anything. The pure stock guys have some strong running cars