That looks like a great idea, I have some Powerstick chambered mufflers on my Duster that might be too loud once I drop in a hot 360. Do you think a 16" long canister muffler would fit in place of those 8" ones in your example?
It's just a matter of clearance side to side between the springs and the tank, and making the full resonator first so you can perfectly set the desired length when hooking it to the tail. Measure 3 times, cut once....then Mig.