Slant six to 318

SlantSixSullivan

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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.
 

Oldiron440

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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.
 
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SlantSixSullivan

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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.

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.
 

Oldiron440

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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?
 

SlantSixSullivan

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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?

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?
 

BudW

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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 (or a /6 to 360 mount kit - which is different), 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 transmission to use, if available. If you already have a transmission but not sure which one – there will be some numbers (transmission part number) stamped on it (as well as date of build and last part of VIN). Record those numbers (or take a picture) and post here. We can let you know what you have.

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 the style you will need (3-piece design was used on all FMJ body’s and A-body’s). A few year other bodies used the 3-piece style 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.
Note: it might be (will be?) simpler to just get a cable kickdown system.

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. Or A.I.R. pump if required.

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, clutch and shroud.

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 (if using a 318 2-bbl). 360 2-bbl has a different size hole.

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.

Alternator

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

BudW

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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
 

BudW

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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
 

Oldiron440

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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
 

BudW

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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
 

Oldiron440

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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.
 

Aspen500

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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.
 

F body Deconstructor Jim

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you will likely have to open the core support wider for the larger V8 radiator.
make sure you get everything you can...rad, shroud, fan, pulleys, etc.
/6 shroud is different than V8
 

SlantSixSullivan

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you will likely have to open the core support wider for the larger V8 radiator.
make sure you get everything you can...rad, shroud, fan, pulleys, etc.
/6 shroud is different than V8

The car came with some sort of aftermarket aluminum radiator, which was gargantuan compared to the stock rad. I know a large one will fit. It never did have a shroud, nor did it need one with that big aluminum radiator. I now have a 360 ready to go in, so I would like to have the shroud.
 

AJ/FormS

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This swap is possible in a weekend if you have previously done it and so all the parts are right there.
For a first-timer, and exhaust scheduling, and a new to you powertrain, I'll guess no way in a weekend. And the older you are, the longer it's gonna take.
I used to do a swap from 367/ 4speed, to a 318/ 904, plus a rear gearchange; twice a year. IIRC, my best time was 14 hours, on a lift with a cement floor. And the same exhaust was used........ and I was only in my early 50s, and in great shape. I used long weekends and took Sundays off.
I think it would be wise to rent a car for the week.... at least.
 

SlantSixSullivan

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This swap is possible in a weekend if you have previously done it and so all the parts are right there.
For a first-timer, and exhaust scheduling, and a new to you powertrain, I'll guess no way in a weekend. And the older you are, the longer it's gonna take.
I used to do a swap from 367/ 4speed, to a 318/ 904, plus a rear gearchange; twice a year. IIRC, my best time was 14 hours, on a lift with a cement floor. And the same exhaust was used........ and I was only in my early 50s, and in great shape. I used long weekends and took Sundays off.
I think it would be wise to rent a car for the week.... at least.

I have a Dakota to get around now. The slant is out of the car, 360 is built and ready to go. It's just a matter of gathering parts, and then doing it. I just bought a house amd the garage needs a ton of work before I can begin
 
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