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'89 f250 engine swap

Discussion in 'Ford Trucks' started by quietrangr, Apr 25, 2007.

  1. quietrangr

    quietrangr Junior Member
    Messages: 3

    I have a '89 f250 4X4 used for hauling and pulling firewood on a tandem trailer. Total weight of load is around 7,000 lbs. The 302 is very weak and is smoking in higher gears at lower rpms. I am considering switching to either a 300 or 351. I don't need to go fast, have rather short hauls. If switching to either 300 or 351, do I need to worry about bolt-up? Will the wires match up? If there is a computer for these years, will that match? Also, just your general opinions and tips. Thanks. Richard
     
  2. Mudman78

    Mudman78 Senior Member
    from NJ
    Messages: 103

    What trans do you have? THe ECU is specific to the engine/trans combo, so any other swap other thyan another EFI 302 will require a computer change and the harnesses will probably not match perfectly either. It is doable and your best bet would be a 351, but it's not as simple as just swapping the motor. If you have a donor truck to get all the parts, harnesses and ECU from, it''ll be easy.
     
  3. quietrangr

    quietrangr Junior Member
    Messages: 3

    the transmission is a c5, which had been switched from the next lighter duty transmission by the previous owner. Complete donor truck does sound like the answer. But the computer going with the transmission sounds confusing. Could the last owner switching transmissions without switching computer be why my idle isn't right, why it stalls easily starting out, and why the engine revs between gear shifts? Thanks for your reply. The first one in two days.
    Richard
     
  4. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    You would need to get the computer that goes with the donor motor. Around here you can buy the donor motor and the computer still hooked up. I did that with a Bronco II. I just unplugged the computer from the junction plug at the fire wall, put wires and everything on top of the engine still connected and pulled the engine. Then pulled the donor computer and mounted it where the old one was behind the passenger side kick panel.
    Your C-5 should be vacuum / speed controlled the only wires to it should be the park switch and the backup light switch. If it's an overdrive 4 speed it will have computer control circuits. This would not be a job for those weak of skills. It also takes time to get the bugs out. I still had to mate the wire harness's together. They do change stuff from year to year that can cause problems with getting the systems to work. The save headaches consider getting a crate motor or a short block and having your heads done. Or your engine rebuilt with a little hotter of a Cam Shaft added for more low end torque. You can go with higher flow injectors and a custom chip in the computer. How much you want to spend, how longs the rest of the truck going to last? Do you really want to spend this much on an older truck?
    You funky Idle can be the Idle Air Control or Throttle Position Sensor or a Vaccum leak or fouling out spark plug.
     
  5. quietrangr

    quietrangr Junior Member
    Messages: 3

    The last engine swap I did was about 30 years ago from a 230 to a 292 inline 6 on a late '60s Chevy. Back then if it fit, it worked. I'm getting nervous about swapping these fancy ones myself, and am going to think about what you said. I really appreciate your advice.
    Richard
     
  6. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    I don't mean to discourage you.
    I have been right where you are a few times with trucks.
    The cost to do what on the surface seems like an easy fix can become real costly. Like a simple wheel cylinder replacement turns into 4 brake lines, another wheel cylinder and 2 calipers.

    In the old days we could switch the engine and all you had to hook up was the cooling system, gas line and power to the coil, hook up the charging system and it would function!

    But the modern systems in my opinion are a lot more reliable. You have less parts fail and few replacements needed during the life of the vehicle. Spark plugs go forever compared to the old low voltage systems.