Engine Cut out at 3500 RPM @ 5 psi

My 92 SC will completly cut out and shut off when I get on it. When I hit about 3500 RPM around 5 psi boost it dies. It then will come back and buck back and forth if I don't let up on it. It broke the harmonic balancer by doing this. It will not do it by just simply reving it, it must be under a load. Any ideas??

I would say that the harmonic balancer is the cause of all your probs. Hopefully you can get whats left off and it did not screw up the crank snout if it did you are goin to need a new crank. The crank sensor prob got damaged from the broken harmonic balancer and that could have taken out the dis module so you are goin to have to cross fingers and get the broken balancer fixed b4 you can trouble shoot any issues.

99% of the time it's bad plugs or wires that causes bucking under boost. Oem wires are easily damaged after being on the motor for a while and may look fine but still be bad.

David