How to determine a safe red-line?

I have the KB107s at +.004deck. Been banging shifts at 6500 to 7200,depending on which cam is in it,etc., for 125000miles,cast crank,stock balancer/flywheel and all. Hughes cams seem to go on forever.Had the motor apart during its early miles to check on it. Found a migrating wristpin bushing once.Pistons were still tight and looking good.The G-Tech will tell you a lot. As usual 67Dart is double bang on.Nice graph, dont let the other-brand guys see it.