Slant six to 318

Engine Swaps

  1. SlantSixSullivan

    SlantSixSullivan Well-Known Member

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    I've got a slant six in my 1980 Diplomat coupe and I am looking at buying a low mile (29,000) 318/904 combo to swap in it.

    A few concerns I have are as follows:

    It is my daily driver and cannot be down for much longer than a weekend.

    Is my current driveshaft going to work with this swap?

    Any linkage differences between a slant 904 versus small block 904?

    I have the Schumacher mounts to convert the K frame, so no issue there.

    Is it possible to get this done in a couple days, provided there are no unexpected catastrophes? I believe it is a lean burn engine, which can be done away with later. Also, I am aware that an exhaust system is necessary to drive the car so I will schedule an appointment to deal with that once I have the engine in.
     
  2. Oldiron440

    Oldiron440 Well-Known Member

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    You will need the proper radiator, hoses etc.. Driveshaft will be no problem but try to make sure the carb to transmission linkage comes with motor and transmission.

    I'd say a direct swap v8 to v8 or /6 to /6 a weekend no problem. This swap is what a week of vacation is for.
    I'd like a v8 parts car fo rob parts from for all the little stuff you don't think of.
    One more thing your exhaust guy is going to have to put cats on in the stock location's so add that in your budget.
     
    Last edited: Sep 22, 2018
  3. SlantSixSullivan

    SlantSixSullivan Well-Known Member

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    My exhaust guy always does exhaust with no cats for me. I was actually just thinking about the radiator after I posted. Wouldn't be a bad idea to re-gasket the engine while I'm at it. I don't have a parts car, unfortunately but I do know of some in the area. The deal I'm getting includes engine, trans, driveshaft, plus all the accessories on front of the engine. I will make sure the linkage is all there and included. The guy says he can drive the car around enough to put it up on a lift, so I'd imagine the linkage is there. Car was wrecked, that's why he's parting it out. By the way, it's a 76 Volare two door, if anyone needs parts I'd be happy to take a look at what's left on the car.
     
  4. Oldiron440

    Oldiron440 Well-Known Member

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    A 76, I would put valve seals in it and mabe a timing chain set. Convert the ignition with a conversion kit while your swapping things. Is it a 2v or 4v carb?
     
  5. SlantSixSullivan

    SlantSixSullivan Well-Known Member

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    2V carb. I would convert the ignition, get rid of the spaghetti vacuum mess, and do new gaskets and seals. That's at the very least. I'd likely rebuild the tranny with a shift kit as well. I was actually looking for a 904 trans for my slant six when I found this deal. So I figured why not?
     
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  6. BudW

    BudW Moderator Staff Member

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    It would be best to have a “parts car” to access for those things you miss.

    In my opinion, it is easiest to have a V8 K-frame to start off with. Install engine and transmission onto the new K-frame. Rebuild the front suspension while there (if needed). Plan on dropping old engine, transmission, K-frame and suspension all at same time (with front of car raised up). Roll old “assembly” out, roll new assembly in, and lower car onto new powertrain.
    This route, you can gather parts, rebuild what is needed to be rebuilt, etc., and perform the change easily in one weekend. Maybe even in one 8-hour day.

    Now with that said – it sounds like you are going a different route – but there is nothing wrong with that. Depending on how you do it, it may take a full weekend for install (or longer).

    IF you already have the Schumacher /6 to 318 mount kit, you already have a A904 (from your old /6) and have a A904/A998/A999 – then your old propeller shaft will be the same.


    Parts you will need for change over (might not be a comprehensive list):
    A 318 and automatic transmission. An A999 would be best, if available. If you have a transmission but not sure which one – there will be some numbers stamped on it. Record those numbers (or take a picture) and post here. We can let you know.

    The /6 and 318 transmission cooler lines will be bent differently. A person might still be able to use them. This easier to do before engine install – than afterwards. Just make sure transmission cooler lines to not rub anything or each other!

    The 318 and /6 radiator necks come out in different locations – so a radiator will be needed. They make two different size groupings of radiators: 26” and everything else (18”, 19”, 20” and 22”). The later 4 will interchange with each other providing /6 to /6 or 318 to 318 (but not vice versa).

    Radiator hoses (which might be needed anyway).

    Throttle cable. The /6 cable is longer – but is “too long” to be helpful. Note: there is a 318 2-bbl and 318 4-bbl throttle cable lengths, as well as a /6 1-bbl and /6 2-bbl lengths – or a total of 4 different throttle cable lengths available for FMJ’s.

    Kickdown linkage. Note: Chrysler changed kickdown linkage designs almost every 2 to 3 years. They also have a 1-piece design and a 3-piece design. The 3-piece design uses 2 different bell cranks – which is what you will need (3-piece design was used on all FMJ body’s and A-body’s). A few year other bodies used 3-piece but a majority used 1-piece designs. What year design you use doesn’t matter – just as long as it came from the same car. Also grab the intake bracket and transmission pivot bracket to have a complete set.

    Wiring harness is different. More specifically, the distributor pickup coil pigtail(s) are in different locations. A small wiring repair can correct that difference – just make sure you use solder and shrink wrap to seal the solder joints.

    Both battery cables.

    Heater hoses are different lengths and routed differently (minor issue). Sense you are now using new radiator hoses, it might be a great idea to change heater hose with new, at same time.

    The alternator, A/C compressor (if applicable) and P/S pump (if applicable) can be reused – but all mounting brackets and P/S pump pulley will be different. Be sure to get a complete set of all pulleys, brackets and bolts for alternator, A/C and P/S.

    P/S hoses may or might not fit. There is a small chance they will fit, but don’t count on it.

    A/C hoses will not fit.

    Some A/C clutches are the same, but most are different (between /6 and 318)

    Cooling fan blade and clutch.

    Most 318 exhaust manifolds will fit – but not all will.

    A /6 2-bbl air cleaner should work. A 1-bbl air cleaner will not fit.

    Performing a Lean Burn (or whatever name is on your computer) changeover – this would be a great time to do – if not beforehand. NOTE: this will add time (two hours, maybe) to the engine changeover.


    Items that remain the same:
    Transmission mount and crossmember.

    The Steel fuel lines (already attached to body). The metal fuel lines on engine will be different.

    Radiator fan shroud (if not changing between the 26” vs all other size radiators, that is)

    Alternator

    Starter – but this would be a great time to upgrade to a mini starter (optional).
    BudW
     
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  7. Oldiron440

    Oldiron440 Well-Known Member

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    Actually the 6 Throttle cable works fine.
     
  8. BudW

    BudW Moderator Staff Member

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    Which one?
    The 1-bbl or the 2-bbl one?
    I tried one, at one time, and it just didn't work (way too long). I just don't recall which one it was from.
    BudW
     
  9. Oldiron440

    Oldiron440 Well-Known Member

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    It's all I've ever used on my 76.
     
  10. BudW

    BudW Moderator Staff Member

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    I lost the folder that had all of the details on throttle cables.
    Going by memory (in other words, don’t use this as the gospel) and some hand written notes I have:
    The FMJ 318 2-bbl cable is about 19 inches long
    FMJ 318/360 4-bbl cable is about 20 inches long (about an inch longer than 2-bbl)
    Imperial Fuel Injected cable is about 20½ inches long
    Depending on the year – FMJ /6 1-bbl cable is 26 or 27 inches long
    FMJ /6 2-bbl cable is about 30 inches long
    BudW
     
  11. Oldiron440

    Oldiron440 Well-Known Member

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    I will say the six cable is long enough.......
     
  12. Oldiron440

    Oldiron440 Well-Known Member

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    I'm glad to have the cable I have now that I'm using the Eldelbrock Victor intake with a 1" spacer.
    20180128_131817.jpg
     
  13. BudW

    BudW Moderator Staff Member

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    Those big engines with tall intakes, do need a longer cable.

    Those wanting to install a 318 2-bbl in place of a /6, I’m thinking there is too much cable – to the point the cable might kink. In your case - it might work fine.

    Is that your engine?
    BudW
     
  14. Oldiron440

    Oldiron440 Well-Known Member

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    That's my 500" 440, I used the M1 intake before witch is lower. If I remember correctly the cable gets a gentle loop with a turn to the carb, I can't imagine using a shorter cable. This intake is 4" taller and I don't think there's going to be a loop.
    This intake is supposed to be the latest and greatest but is within 2 or 3 numbers of the old M1.
     
  15. Aspen500

    Aspen500 Well-Known Member

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    New cables are available. Rock Auto is one source. They have the 19.75" cable and also a 19.25" cable. I assume longer is 4 brl and shorter is 2 brl . They're about $20.