Help choosing a v8 for my dart

Appears to be the factory Commando/Charger 273 exhaust, or a repop of it.
Rustbucket? How can you tell from just the primered tail end? Not everybody can have- or wants- pristine Gold Certified cars. I like it- Rock On.

I'd say it was a 170 cu in slant six with a "little" work to it.