They don't have a false pipe advertised but you can buy each component separately. One could buy another muffler and the cross under pipe for the SS power duel set up and make their own. With the cross under. You would be able to mount it to back of transmission. It wouldn't be cheap.
I have this pipe. Right now it is one a 124 set at 11.4:1 with a 266E. It was on a 124r set at 11.2 and 662-2. Both were softer on the bottom than a X-series TH. It also has a sag in the TQ right around 4000-4500. This same sag shows up on a 103 with 555tqster. So, I don't really know what kind of volume needs to be put through this pipe to make it work. I pulled the muffler and stuck a SC-4 ST muff on it. Fixed the low end. Haven't been able to play to much to see top end results.