In another forum this statement was made recently by one of their "gurus"....."Running the dual t-stat setup without the BRF (bypass restrictor fitting) tends to cook the #7 and #8 cylinders." And it was stated as an undisputed fact. Wasn't this the reason GM designed the '97 cooling upgrade (w/o BRF) to begin with? To stop head cracking and cooking the rear cylinders? And increasing flow through the heads and block by 74%?