We recommend a transmission swap for most older gas powered trucks). The small block “M” or 400 bolt pattern will also bolt up to a 460 pattern, but requires extra grinding and cutting (using one of these transmissions is not recommended, but it is possible. Check out our Cummins Engine Information article for lots of good information on the Cummins engines as they pertain to conversions! Transmission information Automatics C-6: We make adapter plates for the 460 or 6.9 diesel C-6. If you would rather have us do the wiring for you we do offer you modification services for your original Ford engine wire harness. Wiring instructions for 12 or 24 valve engines are sent out with your parts for the specific year of your truck. This will limit your top speed and dramatically increase your fuel consumption unless you plan to use some taller tires. Generally, gear ratios that are lower (numerically higher) than 4:10 are too low for the Cummins engine, especially if you don’t have an overdrive transmission. The 03 Dodge radiator and intercooler work best as well.
These require a bit more work because the power steering reservoir on the Cummins will hit the steering box and the ECM must be relocated for engine mounting. A few guys have installed a 03 or newer common rail engine. Usually the 12 or 24 valve Cummins is the engine chosen for the new power plant in these trucks. If you have a 91-93 Dodge radiator and intercooler, they have been used before by fabricating mounting brackets. If you have an 80-92 style Ford, use the radiator and core support that held a 31” wide radiator from an 84-92 Ford with a 6.9 or 7.3 diesel if you don’t have it already. If you have a 92-97 style Ford use the radiator and core support from a 92-97 Ford® that had 7.3 Power Stroke or non- Power Stroke diesel (with a 31” wide radiator). Diesel and Gas truck radiator supports are different so if you plan to change radiators plan to change the core support as well. These radiators have the hose connections on the same side as the Dodge® radiators making them easier to connect to the Cummins® engine. You may consider swapping in a 96-97 Power Stroke® radiator with the remote fill tank. Radiators that have X braces in between the radiator and the engine or any that are wider than 31” don’t work well in the conversion. Diesel radiators are recommended for extra cooling capacity if your truck currently has a gas engine. This is explained in greater detail in our installation manual. Some adjustment on your firewall and passenger side toe board with a large hammer to make some more room for the valve covers and exhaust is also necessary. General information for all F-250, F-350, and F-Super Duty: You will need to cut holes on your radiator support and also trim the back of your 80-91 grille to allow the intercooler to be installed.