As the proud owner of an ERA with pretty much the same rear end I also would like to know what is going on since this is your second time around. This time you said it was your fault, can you enlighten me.
Coming from 60's era's muscle cars I am hesitant to even smoke the tires with what this rear for fear of what happened to you. The width of the tires the, the grabbyness
of the tires and what appears to be a weaker set up over the solid rear axle.
Nice drag picture in your box.