Once again i laugh at this statement,theres is absolutely NOTHING wrong with using SIR rods when properly prepared,theres a set living quite well in my 416 making 520h.p. with 2+ seasons of racing,and turning the motor to 7000 rpms many times..i have'nt had 1 issue with them whatsoever,like i've stated many times its all has to do with whos machining/building your motor...