My uncle has a 91 F-350 with the 7.3L deisel and an automatic. He was wondering if he could swap in a 351 with an auto tranny from a 87 F-350.

Do they have the same engine mounts?
Anything else that might hold him up?

thanks

 

Size-wise it would likely fit with the proper mounts. Only problem is swapping isn't possible between different engines and transmissions of manyNEWER computer-controlled vehicles because you must also transfer all the computers and wiring for the computer to manage the new engine correctly. Especially when going from a 7.3 to 5.8 and if you're going from diesel to gas? (not sure there are any diesel 351's). If going from diesel to gas you'd likely have to flush the fuel system of the diesel fuel also. It could happen, but it is a big project.

 

Same year trucks are easier to do. You will need to change wiring and mounts. Check each truck to see if the frame is the same. If they are its not to hard. Better to take off bed and cab. It will save lots of work in the long run. Some vacuum lines will be different between gas and diesel. Throttle cable will need changed to. I did an 89. Put a 7.5 in to replace a 7.3 diesel. It was easier than anticipated. We changed tanks because of low pressure pumps instead of mechanical pump. In side the cab we spliced 6 wires for power to tanks and changed the fuel tank switch. One engine mount on the diesel was rivited on. A grinder and an air chisel took care of that. Some items on the fenders will need to be changed. Make sure the electrical harness going through the fire wall has the same connector. If not, change the harness inside.