Plymouth Duster Suspension/Tubbing Question - Drag Racing

I'm pretty sure you do not need the 3" relocation kit or the mini tubs with the Qa1 rear suspension.....and for what it is worth.....before you consider ANY 4-link / 4-bar for drag racing you should understand the why and how to properly tune it. Read a lot about fast Mopars with Cal-tracs .....but never once with the Qa1 set up. JMHO.

I think you started out asking the right questions.