[Jack21]

Not sure you need or want stainless for your exhaust. It's ridicuosly expensive, andalthough it won't corrode (rust), it doesn't control heat radiation.

Preferable is ceramic coated, inside and outside using ordinary steel tubing for the headers and J pipe. The muffler can be coated outside as well. This provides corrosion resistance, heat control, and nice looks for a lot less money.

I can hold my hand to within about an inch of a header pipe on a running engine. It feels hot, but not uncomfortably so. No adjacent plastic items, vinyl wire insulation, relays, etc. show signs of heat fatigue, melting, or damage. A coated muffler will still burn a leg if it contacts bare skin, so I use a coated heat shield.