359 Exhaust

I've seen a similar setup on old Western Stars with the big, long fuel tanks. I'm guessing you're going bigger than 5" with this kit?

Not being there in person I have no idea if this will work but could you extend the pipe that runs between the downpipe and the Y? What about having a specialty welding shop fab up some custom stainless steel elbows to clear the tanks. What about having your fuel tanks shortened?

 

Are you putting the sleeper back on? My tanks were farther back on the chasis than what yours are. I squeezed 6 inch stacks with pickett elbows between battery boxes and the tanks. Perhaps move the stacks to the back of the cab if sleeper is gonna be left off.

 

You are not alone, there used to be several with that set up here. Lincoln shows a multi-curve elbow which may be it. If not maybe see if they will work with you. Send your old ones back with the new ones. They can use them for a pattern to make yours plus add them to their product line.

 

That shiny stuff always turns into a pain. Gotta love it. You're a more patient than I am, looking for a logical solution, I would already be drilling the frame to reposition the tanks.

....and peeling the white film off a new set of step boxes.