Hey Clay- For something as light weight and non critical as a heater scat tube you can make your own adel clamps in any size out of strap. Debur the edges and either wrap it in silicon tape or smear the edges with rtv and let dry before installing so vibration doesn't have its way with the scat over time. You can also make it look a bit more like a regular cushion clamp by covering the edges in that throw away plastic piece that comes on band saw blades if you happen to have one that you haven't thrown away yet.
If it's just a matter of keeping it from rubbing on a sharp corner or engine mount tube or whatever you can just glue it to the touch point with RVT. Temporarily hold it off the touch point with tape, a popsicle stick, safety wire, whatever is handy just so theres a small gap, then fill the gap with RTV. When it dries, remove the temporary positioning device.
Here's a picture of how I dealt wit a hot spot at the corner of the battery box.