Without dyno info everything is just a guess. Rear wheel info is way more usable than flywheel readings as everything parasitic is in place during the pull. Crude injection, while reliable, will never give the power readings of a good carb set up. Corvettes with the Rochester injection always got their butts whipped by the carbed ones. We have built a few hot I6's but NEVER one without a 12 port head. Before the Atlas we put a 240/300 Ford and even one Slant 6 Chrysler in Chevy trucks. After just 70 years GM finally gave performance inline guys something to work with. Now if Jerry would just his idea engine purring on the dyno we have a couple of candidates waiting. Old age, weak muscles, and bad eyes must now wait on the young(er), strong, and smart.
