We are getting ready to start fabbing up the drive shaft hoops and during that exercise I'd like to build the exhaust along the way.

I am contemplating using oval tubing from the headers, h-pipe, through the muffler and then back to round for the tail pipes (shock clearance) OR just routing the oval tubing right in front of the front leaf spring hanger w/ some 45 deg sections.

My last system of 15 years was 3" round, h-pipe, and routed the front of the spring hangers. I really liked it and rarely drop the 1/4 windows so it wasn't fumey in the car.

Also adding to the complexity is installing cut outs for nitrous use. I didn't figure that a full length exhaust is a good plan for a nitrous hit. Am I off base on this? My last exhaust system more or less burned the mufflers off like a barbecue and the thin metal rusted away at the welds. I'd like to avoid that considering the cost of materials.

Should I bite the bullet and go with 304 SS? I don't know much about MIG welding stainless.

Any thoughts are appreciated.

For vendors, it seems like a few places have oval tubing and such.

I like the idea of tail pipes for a more civil ride however the simplicity of a short exhaust system that divorces at the "H" is very appealing. I could have the old system off in ten minutes or less depending on how hot the car was.