How close it too close?

[davepl]

My exhaust was installed by the body shop long before I reassembled the truck (frameoff teardown). As a side-effect they didn't take into account the parking brake cables and the tank fuel line.

The plastic-coated parking brake cables, even after re-routing one side, are about an inch away (sideways) from the pipes.

The rubber section of fuel line that runs between the cab line and the frame line (it's there for flex, I imagine) is 1.5" above the exhaust pipe.

On the plus side, this is about mid-truck, so it's not just off the collectors or anything.

I wrapped each of these sections with DEI Titanium Exhaust wrap (woven from lava rock fibers!). It withstands 1800F direct and 2500F intermittent, but its really more about insulating the rubber hose for me.

Is an inch and a half air gap enough with an insulated pipe? I figure at idle when no air is moving its under very little load, and under a lot of load it'd have a lot of airflow. But it's really a SWAG.

I also added a reflective heat tube around the fuel line. So they're both insulated and now with about an inch air gap. And I suppose the fuel hose gets cooled by fuel, though not much at idle.