.87 or .89 torsion bars wanted for 65 Barracuda

I appreciate the heads up and useful information. Thank you! Am I understanding that correctly that the strength of the torsion bar was determined by the engine HP/ torque as engines became larger and offered more power, larger diameter bars to accommodate that?
Correct, but nowadays handling is also on the table. I'm putting 1.03 bars in a 66 slant Valiant for improved cornering and handling.