I did look at the QA1 shocks and I've heard they're a high quality product but they don't appear to offer different lengths... QA1 shocks are all 23.6" extended, I was looking for something around 25" based on 2-2.5" longer than stock. Its only about 1.5" of difference and may have been absolutely fine but I was worried they would be in danger of topping out on extension during a hard launch with the 02/03 Superstock springs.
For the longer length shock in the rear of my E-Body, I switched to AFCO. This was on a stick car with a stroked RB. On launch, the rear tires were hooking for a split second and then jumping off the ground when the body separation happened.
I sent them in to AFCO. After I explained what was happening, they advised me to have the valving made stiffer on the extension stroke. I also verified that the suspension travel on compression allowed enough stroke without bottoming.
I'm running the single adjustable QA1's on my '68 A-Body and on the front of my 1970, and love them. I have previously tried Bilsteins and Koni's, but prefer the QA1's.