Here's Superformance 2040 with Roush 427R-095 data that I'm reasonably certain is accurate after looking at things upside down, backwards and inside out. The actual test runs were for acceleration in gears 1 thru 4, but I used 3rd gear for a solid power reference. I grouped the changes I've made to my car from original new as delivered Stage 1, then Stage 2 then Stage 3.
The most noticeable changes in power came from the Pro-Systems carb Stage 2 and Buckshot Racefab side pipes Stage 3 which required going up an additional 3 jet sizes. Subtle changes in power came from 2" primary headers and larger surface area air cleaner. The fuel line change in stage 3 had no change in performance in 1st, 2nd or 3rd gear under load, though seems to prevent lean stumble at top of 4th gear around 135 to 140 mph when using 27" tall rear tires. The aluminum flywheel took away drag race acceleration at shift points because of rotating mass inertia loss as the next gear hit, but added for a street driving snappier rolling punch and seems to aid in having the tires hook better in 1st and 2nd gear over slightly uneven road conditions. The Aluminum flywheel did nothing for quicker shifts, and had no value to power gain or loss under load out of gear shift range.
Here's a Dynojet, wheel HP pull for another perspective of my "Stage 3", current set up.
475.3 wheel HP, 459.3 Tourque
