5.9 Weighted Flexplate

If the 727 trans and converter are neutral balance, you'll need the flex plate that goes with the 5.9. The 5.9 flex plate and harmonic balancer are matched to the 5.9 to externally balance the motor. It too needs one converter hole elongated. The 5.2 flex plates are neutral balanced and need one converter hole elongated to fit the 727 converter.

I have two 5.9 flex plates in my garage. Pay for the boxing and shipping, and I'll send you one.