67mustang302

2 different dynos is a big red flag right there. But use the same dyno you just did, and try swapping headers, then swap back, and swap rockers etc. Try different header/rocker combos since that changed. Maybe part of it, is it had better VE with the other rocker/header setup? Between that, a different dyno and break-in time that's prolly where the numbers differ. In the end though what really matters is how it performs, so don't get hung up on dyno numbers too much. You could just try running it as is, then swapping headers/rockers and running it again, and check lap times. You don't necessarily want more power, but you do want to be faster.

w8less

i bet its the different dyno and the motor isnt broke in. remember dynos are just a tool where it really matters is at the track

my77stang

could the be cam too, one could be advanced or retarded in relation to where the other cam was ground/installed. everything from the actual grinding of the cam to the slack in the timing chain all play into that.

89gt347

dyno where you usually dyno. Every dyno is going to give different numbers.