Is that a tractor trailer muffler? What you looking for you can find at airbagit.com. Those are the old Radical kits they are the only ones that sell the kits still(I think).
Radical also made a targa kit I installed on a Buddy's 88 Blazer. Those kits are cool but they have a tendency to leak. So if this is your daily you might want to think about that. Good luck with the vert.
well that's not the stock motor, on the carb i had to mess with the fuel to air mixture so the truck is running rich and hell, I also got her dyno'd at 97hp to the wheels