Is their any aftermarket true dual exhausts for a 92 Caprice 305?

Finding a readily available, bolt-on true dual exhaust system for a 1992 Caprice with the 305 is unlikely. The aftermarket for these older cars, especially for performance parts beyond basic bolt-ons, is limited. Most exhaust options you'll find will be either single exhaust systems or dual exhaust systems that merge into a single pipe before the muffler.

To get a true dual exhaust (two separate pipes from headers to the mufflers), you'd likely need a custom fabrication job. This would involve:

* Headers: Finding or having custom-made headers that accommodate true duals.

* Pipes and components: Sourcing the necessary pipes, bends, mufflers, tips, and hangers.

* Installation: Finding an exhaust shop skilled in custom fabrication to weld and install the system.

The cost of a custom true dual exhaust will be significantly higher than a readily available off-the-shelf system for a more modern car or even a more common classic muscle car. Before embarking on this, consider the cost versus the potential performance gain. The 305 isn't a particularly high-performance engine, so the improvement might be modest.