[01chevduramax]

The couple that I’ve seen have the engine far enough forward to clear the stock down pipe. I recessed the center of the firewall and make the opening larger to clear the heads. Probably 6” recess and 3” total on each side wider. I further recessed a box to clear the hot side pipe leaving the stock turbo. There is no room inside the frame to run exhaust in the passenger side. The transfer case to frame rail clearance in a few inches. That’s why most guys run a ford high pinion Dana 60 to be drivers side drop. I didn’t want to do that. A classic Chevy is passenger drop. That’s why the exhaust is outside the frame. I had to notch the cab supports a bit to give clearance without the pipe showing under the truck. It will all be heat wrapped.