I kind of like the sound of the stock exhaust. The one guy I was racing with said it pipe made it sound like a hotrod and it sounds mean and deep. I understand a ddm for the firehammer will fit but I don't know if you will have to hack up the body. The hummer body is really wide and there is about a 1 inch clearance between the body and frame at the rear.
DDM "Dominator" Chrome Torque Pipe for:
FG MT5 Monster Truck
FG Monster Beetle
Duratrax Firehammer MT
XTM Grizzly
DDM Inventory Item fd140
from
www.davesmotors.com