Horsepower for a 5.9 Cummins engine varies from 160 to 180, depending on the model year and transmission type.
*Additional details and more data can be found on Cummins Hub.
For more about a Cummins swap, check out these blog articles—Cummins Allison| A Popular Conversion, Diesel Cummins Conversion Adapter Kits, The Popular Ford Cummins Swap, Which 6BT Cummins is Best for Your Swap, and 24 Valve 5.9 Liter Cummins Specifications.