I would take a swing from the start..Full stiff up front, if you can tie ir down to little to no travel even better. I might go 1-2 sweeps from full stiff on the rear at first and then look at the data. I would agree as old as they are they are likely dead. Lower tire pressure as well in the rear. FWIW we run the NA car at 9.4-9.75 and that is a 29.5x10.5 tire, not a W.

As for the launch RPM there area few schools of thought. Some of the fastest cars out there leave as low as the combo will tolerate. Making a "run" at the convertrer. That number seems to vary combo to combo. I am a koolaid sipper in that theory myself with a converter car. We leave very low with the NA 10.5 car. I was a non believer until I did it with mine, ended up leaving at 3900 in a car that made no power below 7700. That led to the best ET's and quickest 60' times for me. The current car we leave at 4200 with a similar power band. Just something else you may or may not want to try.

You have a way to collect and read data now. That will help a ton. My guess is you will end up with new shocks, a lot less tire pressure and eventually a much looser converter...