* Cummins 6BT: This engine came with different turbocharger options depending on the specific application (truck model, year within the model year, etc.). There's no single "size" but rather a range of turbos with different turbine and compressor wheel sizes, A/R ratios (area to radius), and overall performance characteristics.
To determine the size of the turbocharger on *your* specific 1992 Dodge Ram diesel, you need to:
1. Identify the engine: Look for an engine code or identification number (usually found on a plate on the engine block).
2. Find the turbocharger model number: This is usually stamped on the turbocharger housing itself. This will give you the most precise details.
3. Research that specific turbocharger: Once you have the model number, you can research its specifications online, through parts catalogs, or from turbocharger manufacturers.
Without knowing the specific engine and turbo model, it's impossible to give you a definitive size.