My experience is that when the numbers don’t work out, it falls into one of these catagories.......
-the dyno numbers are happy, or if the motor wasn’t dynoed, it doesn’t make what it was “supposed to” make
-actual track weather conditions are way way below “standard” conditions
-the “car” has issues
Usually....... it ends up being a combination of all 3.
My friends Stocker will beat the Moroso chart even in the middle of summer.
It just takes someone willing to keep tweaking the combo...... which means buying and testing a bunch of parts........ most of which will end up not working.
Most bracket guys bolt it all together....... and then iiwii.