Its sprung weight, and anybody that can put 1300hp to the pavement successfully in a handler is not on moparts, that is way beyond anything we can even dream about. Few if any chose an IRS for drag use, so that would not have been their market design target. A 9" or QC would have mt first choices if I was in their shoes. Strange.
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
