Are these pushrods for a solid flat tappet lifters or are you running a solid roller lifter cam with these pushrods?
BTW, I think you should recheck the lift at the retainers with a dial indicator with checking springs and then again with the race springs That can be very enlightening as Fast has already pointed out, pushrod defection is directly related to the pushrod diameter and wall thickness as well as quality of parts used by the manufacturer