360 to replace 273

Small Block Mopar Engine

  1. cudajim

    cudajim cudajim

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    I have a 67 Barracuda and am thinking about replacing the 273/904 with a 360 engine. I need to know what's different and what to expect with this swap. The car was original with a 273/904 but it's tired and I really don't want to rebuild it. I'm concerned with issues related to cooling, exhaust, oil pan, balancing etc. One more thing, I am currently running a single Accurate exhaust setup for a 318 engine (it's bigger pipe than stock exhaust).
     
  2. dano

    dano Evil Handy Man

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    They are the same size physically. The only difference is the 360 pan is wider, Balanced differently, and has a different drivers side motor mount. Been done a million times so those who have done the swap will chime in on how to handle the balance issue.
     
  3. Lonewolf3165

    Lonewolf3165 Living the Dream!

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    You''l need a balanced converter(with the weights on it or get a weight kit for it) or a weighted flex plate that is specifically balanced for a 360. The driver's motor mount bracket is different on a 360/3farty. Use the 360 oil pan & the harmonic balancer is a must, which means the 360 timing cover too. Everything else is a go! Have fun!
     
  4. Wheel Chock

    Wheel Chock Well-Known Member

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    You can use the stock radiator if you use the 273 water pump and timing cover. If you use a 360 pump (recommended) you will need the 360 timing cover and a radiator for a 1970 or later A body. That's in addition to the torque converter and mount issues already mentioned.
     
  5. cudajim

    cudajim cudajim

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    So so far I'm reading that I need to address the motor mount, timing cover, radiator, & flex plate. What about exhaust?
     
  6. johnmucci

    johnmucci moparmucci

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    check out this website for motor mounts..I used them and they work great

    http://www.engine-swaps.com/Pages/ProductsYear/67.72aBody.html#head1

    I also did a 273 to 360 swap...make sure your transmission is a 67 or you will have additional issues..there is a couple of good threads on here you can find. I used the 273 water pump and pulleys etc and just bought a new champion radiator and my car is fine and I live in florida and have vintage air.
     
  7. 67Dart273

    67Dart273 FABO Gold Member FABO Gold Member

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    In addition to above, If you are going to use your original transmission, you'll need a bushing to go over the outside of the older smaller torque converter pilot, and fit the larger, newer 360 crank register

    If you use the old style water pump, which puts the lower output on the correct side for your existing radiator, the timing marks won't be useable, and I'm not sure whether/ not you can mix the new balancer with the old timing cover. You do NOT want to use the old balancer on the 360. What this means is, if you can use the proper/ new balancer with the old timing cover, you'll have to use a piston stop and remark the balancer.

    THIS IS NOT a big deal, I can step you through that.

    If the new balancer will not work with the old timing cover, you'll have to use all new style timing cover/ water pump, which then puts the pump outlet on the wrong side. So you'll need either a new radiator, or to have the lower outlet swapped side--to side.

    I "cheated" on mine. I'm using all--new style water pump/ timing cover, but the old radiator. I have two hoses of unknown origin, which runs under the balancer in the front corner of the K member to "get to the other side."
     
  8. abodyjoe

    abodyjoe Well-Known Member

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    the early transmissions also had a different spline count . if you need any kink of performance converter they are expensive..
     
  9. Rocky_JS

    Rocky_JS 'cuda

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    I was going to say the converter is different size at the register. I didn't know they made a bushing for that... do you have a link?
     
  10. 67Dart273

    67Dart273 FABO Gold Member FABO Gold Member

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    There have been threads here, I'm not sure. Easy to make if you have a friend with a lathe. They are simply a ring of proper dimensions to bush the small converter to larger crank. Sorry don't have that info
     
  11. johnmucci

    johnmucci moparmucci

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    I believe for the pilot bushing you would need to find "Torqueflite Patty" that is what I saw on a thread.... on my 360 build I used a 66 904 but had huges make a convertor for me and used a balanced flex plate.....I'm running 425 hp and the 904 works great!!
     
  12. Lonewolf3165

    Lonewolf3165 Living the Dream!

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    273 timing cover has the bolt on tab for the timing marks & it positions it on the other side. He will need to use the 360 balancer so the marks won't work. Gonna have to use the 360 timing cover too.
     
  13. 66dartman

    66dartman Well-Known Member

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    As far as exhaust goes, dual is preferred, but if you want to keep your single hopefully it's at least 2-1/2". On your 67 I'm not sure if you need a specific manifold to clear the drivers side. There are quite a few headers made for your application, tti and Dougs are 2 that come to mind.
     
  14. cudajim

    cudajim cudajim

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    This is sounding worse as it goes along. I can get the rebuilt 360 engine for 400 bucks with a new cam, lifters & timing chain. For the 360 I'd need to buy - oil pan & pickup, radiator, hoses, exhaust system, exhaust manifolds, transmission, motor mount, kickdown linkage, throttle cable & more just to drive it occasionally. Maybe I'll just stick with a 318 until I have the proper budget to do it right. I was hoping for a cheap swap.
     
  15. dano

    dano Evil Handy Man

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    Depending on the year of the 318 you'll run into some of the same issues.
     
  16. dano

    dano Evil Handy Man

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    If the 360 is from a car you won't need a pan or pick up. Reuse your water pump, cover, hoses (if good), radiator, and manifolds/exhaust. You just won't realize it's full potential, but can upgrade them later if you see fit.
     
  17. 67Dart273

    67Dart273 FABO Gold Member FABO Gold Member

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    I agree with Dano. There's a lot of stuff you can shed from that list.

    1---You can buy used oil pan, but a "factory like" replacement Milodon pan can be had from Summit, etc, for 80? bucks or so

    2--Radiator--As I said I'm using mine with the new style pump, just cheated and ran a hose across underneath. You can have your outlet switched, or as I said, you MAY be able to swap the old style timing cover /pump, use your 360 balancer, and remark the timing marks. I can step you through that, (piston stop) and it's pretty easy

    3--Manifolds--you can use your original manifolds, it just won't "be the best" for performance until you either get better manifolds or afford headers

    4--Transmission--no need to change the trans unless your's is in poor shape. The adapter ring is no big deal, and you can buy an aftermarket B&M flex plate to cure the balance problem

    5--Motor mounts. Believe it or not when I first put my 360 in place of my 273, I modified the existing 273 mounts. Easy to see once you get them out of the car and onto the 360

    6--Kickdown/ throttle is going to depend on ingenuity, type of manifold, carb, etc. I'm still using the factory 2bbl throttle cable on mine, has been Carter 600/650 cfm, now Holley 4bbl EFI. I admit I'm using a manual valve body, so no kickdown
     
  18. funwithfuel

    funwithfuel Well-Known Member

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    I had not noticed if you mentioned which style 360 you are using will you be using the Magnum or will you be using the earlier 360 LA. there's a few more difference is if you're using a magnum
    .
     
  19. moper

    moper FABO Gold Member FABO Gold Member

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    You'll need a custom convertor if it's the earlier splines as Joe mentioned - but I think that was stopped in '66. You might want to ask in the "early A" area to be sure...
     
  20. cudajim

    cudajim cudajim

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    Ok, so I decided to buy the motor, it's not a magnum 360,it's a rebuilt LA engine. I'm going with my original 904 xmission and plan to go with balancing the flex plate and using my torque converter. My radiator is crap so I'll go find or buy a new one with the outlet on the passenger side. That way I can use all the existing stuff on the front of the 360 and can see the timing mark. The existing exhaust manifolds will work as will the exhaust system. I will also have to change the power steering pump/brackets with a newer system (junkyard item). I already have a center sump oil pan on the way.

    This will be an interesting project, I'll keep you all posted on progress. Thanks for the comments so far.
     
  21. cudajim

    cudajim cudajim

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    Yes, the system I have is from Accurate and it's 2-1/2". I've already confirmed the factory manifolds will work too, it's not optimal but it'll work and it's cheap (my favorite brand).
     
  22. leblanc

    leblanc member 2883

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    Enjoy the increase in power, if your old rear end is a 7 1/4 you might consider the 8 1/4 or 8 3/4 unless you go very easy with your right foot. The old 7 1/4 will take "some" abuse but not a whole lot. Like I said if you go easy the 7 1/4 should last a while...mine did(5 years). The 8 1/4 I have now is much more fun, I can even abuse it if I want.
     
  23. cudajim

    cudajim cudajim

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    I already have an 8-1/4 rear end but have to get better gears. The old pig has 323 gears but needs to be rebuilt. If anybody near Sacramento has a good pig with 323 gears let me know.
     
  24. Jim Lusk

    Jim Lusk Well-Known Member

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    Jim, one thing not mentioned is the heads. They likely have smog pump holes below the exhaust ports. Tap them and thread some bolts in and cut them off (or use some allen-head set screws). Use some sort of loc-tite to keep them permanently in place.
     
  25. cudajim

    cudajim cudajim

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    They're already sealed off and ready to go.
     
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