75 Duster i6 to V8. easy swap?

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cruisebrothers

cruisebrothers

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Hello all,

At the moment i got a 66 289 Mustang. I want to join the Mopar club and decided to go for a A- body
Here in the Netherlands Mustangs are easy to find (however still expensive).
I want to go for a Plymouth Duster. There are only a hand full for sale at the moment in a 600 mile radius.

There is a 75 Duster custom with the leaning tower of power for about 12K USD (VH29C5B). Its in overall good shape with working gauges etc. It got the torqueflite 3 speed and front power disk brakes.
Next there is a 71 Duster 318 for 28K USD. Condition is not that good and the hood is with some ugly aftermarket scoop. Not all gauges are working.
For about 48K USD i can find a 70's 340 (good condition).

I am considering the 75 custom i6 as it looks to be the best deal.
In the future a maybe want to swap in a 318 or 360 engine. I think this still will be cheaper as buying the worn 71 318 for 28.
Am i right? or am i missing something?

Thanks all!
 
Going from a slant to a v8 (if you have a the V8) it either requires a V8 K-Frame or swap motor mounts, that do exist that puts a V8 in a slant 6 K-Frame.

K-Frame can be tricky as there are two V8, 72-down "Biscuit" mounts or 73-up "Spool" mounts. Both have different engine mounts and sway bar attachments.

I would buy the nicest one with what you want if you plan to keep it mostly stock or slightly modified. Things I would look for is disc brakes and a 8-1/4 rear end.
 
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Wow prices are high there. Nothing wrong at all with a slant, today you can get power out of them if you want to. Schumaker had conversion mounts and so do alot of other companys if you want to go that way without looking for a LA crossmember, taransmission, driveshaft etc.
 
Thanks all.


So just to confirm: there is no welding required for the motor mounts when using the correct K-frame? Would welding be necessary when using conversion kits like Schumacher?
I’ll keep my eyes open for a nice engine, transmission, and the other parts I might need. Maybe in a couple of years I can do the upgrade. Then again, maybe the I6 drives so nicely that I’ll just keep it as it is.

I’ll be test-driving the car tomorrow (after a 500-mile trip to see it). I’m looking forward to experiencing the I6. I especially love the sound of a V8, though. Is it possible to make the I6 sound a bit more aggressive or give it a bit of a growl as well?

The V8 318 manual car I drove before (the one for 28K) drove terribly.

I’ll keep you posted!
 
cruisebrothers said:
Thanks all.


So just to confirm: there is no welding required for the motor mounts when using the correct K-frame? Would welding be necessary when using conversion kits like Schumacher?
I’ll keep my eyes open for a nice engine, transmission, and the other parts I might need. Maybe in a couple of years I can do the upgrade. Then again, maybe the I6 drives so nicely that I’ll just keep it as it is.

I’ll be test-driving the car tomorrow (after a 500-mile trip to see it). I’m looking forward to experiencing the I6. I especially love the sound of a V8, though. Is it possible to make the I6 sound a bit more aggressive or give it a bit of a growl as well?

The V8 318 manual car I drove before (the one for 28K) drove terribly.

I’ll keep you posted!
Click to expand...

No welding if you use a V8 K-Frame and the matching factory V8 engine and K-Frame Mounts or if you keep the slant K and use swap mounts. The easiest rout is swap mounts. 273/318 have a different drivers side mount than 340/360, so order the correct swap mounts for the engine your using.

There are slant speed parts so yes you can add some power to them. Folks have turbo'd and super charged them as well.

Which slant is in the car you're looking at? There are 3 sizes I believe.

What was up with the 318 car?
 
cruisebrothers said:
So just to confirm: there is no welding required for the motor mounts when using the correct K-frame? Would welding be necessary when using conversion kits like Schumacher?
Click to expand...
No welding.
It will need either the correct K-frame or the Schumacher conversion brackets and a little grinding.
The engine will also need the correct brackets or mounts. As mentioned earlier in the thread, older models used a flat rubber mount and the year you are looking at uses a spool mount.
cruisebrothers said:
I’ll keep my eyes open for a nice engine, transmission, and the other parts I might need. Maybe in a couple of years I can do the upgrade. Then again, maybe the I6 drives so nicely that I’ll just keep it as it is.
Click to expand...
If you do get a new engine-trans combination, make sure you get all of the throttle and transmission linkage with it, and all of the brackets for the alternator etc.
cruisebrothers said:
I’ll be test-driving the car tomorrow (after a 500-mile trip to see it). I’m looking forward to experiencing the I6. I especially love the sound of a V8, though. Is it possible to make the I6 sound a bit more aggressive or give it a bit of a growl as well?

The V8 318 manual car I drove before (the one for 28K) drove terribly.
Click to expand...
The early 1970s saw a lot of emissions related changes that impacted performance, especially on the timing of the slant 6. Maybe export models were exempt.
The 318 should be great if in good shape and with the proper timing curve.
Coming from limited experience, start with something that is running pretty good.

On a '75, bypassing the OSAC valve will take of the delayed part-throttle timing advance.

Vapor capture systems in the 1970s don't harm perfromance. But sometimes the charcoal from the canister will migrate into the carburator when the filter material degrades. That can also make an engine run poorly.
Mattax

Post in thread 'Charcoal Can Fans, should I?'

The emissions systems are reviewed in the Master Tech Conference.
Scroll down here to the year of interest and see what was new, and hten checkthe year before as well.

Master Technician Service Conference - Chrysler's Training for Mechanics

The Imperial Mailing List Online Car Club is dedicated to the preservation, appreciation and restoration of Imperials and Chrysler Imperials of all years, models and body-styles.
www.web.imperialclub.info
If looking at the html is a pain, go over to www.mymopar.com and get it in pdf or youtube format.
go-fish said:
View attachment 1716027535

Does this component tie into the mix?
Click to expand...

No. Its part of the OSAC.
Basically a delay on vacuum spark advance to reduce NOx with increasing speed. Also incredibly annoying from a drivers point of view/
Cleaner Air System...

Some '75 engine K-frame, and electric info just posted here
Mattax

Post in thread 'Just purchased a '75 Dart Swinger going to ask a ton of questions.'

Since its a swap. A couple of other things that are worth checking.
Throttle linkage and transmission "kickdown" linkage. Everyone calls it "kickdown" but its main function is to adjust pressure in the transmission as the throttle position changes. More throttle => increasing pressure in that circuit of the transmission. This is very important.




Main circuits.
1975 was unique is a couple of ways. The important thing to know right now is that unlike earlier cars, there are two fusible links. This...
 
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Consider this
The trans from a /6 won't bolt up to a v8 unless it's a stock and you get a v8 bell housing
Motor mounts are different
Exhaust is different
Radiator is different.
All of that costs money.
All of that needs to be found. And picked up or ordered.

For this reason when I got my most recent/6 vehicle (85 D150). I decided that for all the money the parts that are different (and of which I don't have) would cost. It would be cheaper to keep the /6 and "build a better mousetrap" out of that. I ain't racing it, I plan to daily drive in any season there's no salt or brine on the roads.
Rusty, Charlie S, Greg ("slant six") Darter6, and others here can guide you.
In my case I already have another similar truck, an 83 D250 that started with a v8. That truck is currently taken down to a bare frame, the body is in paint jail the rest is here that I'm working on. That is gonna be my camper hauler.
 
Enjoy the slant six for awhile. I have a dart with a slant and even though it's a slow car, it runs nice and smooth after it warms up. If you want to swap it for a V8, do what I'm doing and slowly get everything needed to do the swap as easy as possible. Don't take the car apart until you know it's ready. A mistake people make is taking the car apart and then having an unfinished project. Build and get what you need on the side, and leave the car whole and enjoyable in the meantime. Who knows, maybe you might change your mind after experiencing Chrysler's slant 6 and keep it a six cylinder.
 
And I've had /6 cars that were slugs then the next was surprisingly peppy... My 80 volare and moms 79 lebaron were among the better running, along with the first 225 that I had in my 79 d100. The replacement 225 in the truck was horrible.
(Original engine killed the cam gear, was stock original unmodified engine)
 
I did it twice with the swap mounts.
The ‘75 will use the Schumacher mounts from creative services. Perhaps Mancini may have them in stock @ Manciniracing.com
 
cruisebrothers said:
Thanks all.


So just to confirm: there is no welding required for the motor mounts when using the correct K-frame? Would welding be necessary when using conversion kits like Schumacher?
I’ll keep my eyes open for a nice engine, transmission, and the other parts I might need. Maybe in a couple of years I can do the upgrade. Then again, maybe the I6 drives so nicely that I’ll just keep it as it is.

I’ll be test-driving the car tomorrow (after a 500-mile trip to see it). I’m looking forward to experiencing the I6. I especially love the sound of a V8, though. Is it possible to make the I6 sound a bit more aggressive or give it a bit of a growl as well?

The V8 318 manual car I drove before (the one for 28K) drove terribly.

I’ll keep you posted!
Click to expand...
I bought it!
I just opened a topic in the welcome wagon: Hello from Holland - 75' Duster
Will add info to this topic later regarding the I6.
 
dano said:
No welding if you use a V8 K-Frame and the matching factory V8 engine and K-Frame Mounts or if you keep the slant K and use swap mounts. The easiest rout is swap mounts. 273/318 have a different drivers side mount than 340/360, so order the correct swap mounts for the engine your using.

There are slant speed parts so yes you can add some power to them. Folks have turbo'd and super charged them as well.

Which slant is in the car you're looking at? There are 3 sizes I believe.

What was up with the 318 car?
Click to expand...

This is the 318 car:

Bekijk deze Plymouth Valiant Sport Coupe / bij Auto Mooij Classics

Its far from stock. The paintjob is bad (dripping paint). The vinyl top is peeling and cracking. The gauges including speedo did not work. The engine feeled ok but didnt like the manual shifting. There is a aftermarket hood scoop added and the hole in the hood is very rough. Current price is 31000 US Dollar. I paid 11.750 for the Slant 6 which is in far better condition (beside some dents I will fix later).
 
Just saw the car in the other post. It's pretty nice the way it is, which now makes it a little bit harder to justify a V8 swap, lol. Enjoy that slant 6, keep it happy and it will keep you happy in return despite being slow, but that's part of the humble charm.
 
I swaped out the slant 6 for a 273 v-8 in my dart had to change the k-frame and get a bell housing to fit the 4- speed
 
Thanks all.
Not sure what to do yet. First have to get the thing and will try how the I6 will perform on my 500 Mile trip back home. Maybe it will just suit me right.
However. the sound of a V8.
This weekend I got my Mustang 289 dig out of the garage for the first time this year. After 5 years I got it running right finally. There is a flowmaster exhaust system on it and it sound just so good...
Got it for sale on sunday and sold it in monday...
I will miss the 289 :( But looking forward to get the Duster!

Ant said:
Enjoy the slant six for awhile. I have a dart with a slant and even though it's a slow car, it runs nice and smooth after it warms up. If you want to swap it for a V8, do what I'm doing and slowly get everything needed to do the swap as easy as possible. Don't take the car apart until you know it's ready. A mistake people make is taking the car apart and then having an unfinished project. Build and get what you need on the side, and leave the car whole and enjoyable in the meantime. Who knows, maybe you might change your mind after experiencing Chrysler's slant 6 and keep it a six cylinder.
Click to expand...
Will do the same, Just find the parts. It will be a fun project.
Do i need to change the torqueflite that's on the Slant now or only the bell housing? (when using a 318?)
Cant wait to check if I got the 8-1/4 rear end. It got the Rallye Rims so 4.5 bolt pattern. (and disc brakes)
 
cruisebrothers said:
Thanks all.
Not sure what to do yet. First have to get the thing and will try how the I6 will perform on my 500 Mile trip back home. Maybe it will just suit me right.
However. the sound of a V8.
This weekend I got my Mustang 289 dig out of the garage for the first time this year. After 5 years I got it running right finally. There is a flowmaster exhaust system on it and it sound just so good...
Got it for sale on sunday and sold it in monday...
I will miss the 289 :( But looking forward to get the Duster!


Will do the same, Just find the parts. It will be a fun project.
Do i need to change the torqueflite that's on the Slant now or only the bell housing? (when using a 318?)
Cant wait to check if I got the 8-1/4 rear end. It got the Rallye Rims so 4.5 bolt pattern. (and disc brakes)
Click to expand...
The transmission case is different and are not interchangeable from I6 to V8 and vice versa. It's probably best to find a cheap core and have it rebuilt, don't trust the sellers when it comes to transmissions.
 
cruisebrothers said:
Hello all,

At the moment i got a 66 289 Mustang. I want to join the Mopar club and decided to go for a A- body
Here in the Netherlands Mustangs are easy to find (however still expensive).
I want to go for a Plymouth Duster. There are only a hand full for sale at the moment in a 600 mile radius.

There is a 75 Duster custom with the leaning tower of power for about 12K USD (VH29C5B). Its in overall good shape with working gauges etc. It got the torqueflite 3 speed and front power disk brakes.
Next there is a 71 Duster 318 for 28K USD. Condition is not that good and the hood is with some ugly aftermarket scoop. Not all gauges are working.
For about 48K USD i can find a 70's 340 (good condition).

I am considering the 75 custom i6 as it looks to be the best deal.
In the future a maybe want to swap in a 318 or 360 engine. I think this still will be cheaper as buying the worn 71 318 for 28.
Am i right? or am i missing something?

Thanks all!
Click to expand...
So having had a time in Germany I have to give you the warning that TUV will scrutinize any welded parts. Your best option would be to find an original K frame with mounts or use the swap mounts they talked about. Not sure if you have to pass TUV but in Germany they were…
If you stay with the 904 transmission all your linkages will work with the V8 transmission. You could even just find a v8 housing and swap the internals over.
 
Ant said:
The transmission case is different and are not interchangeable from I6 to V8 and vice versa. It's probably best to find a cheap core and have it rebuilt, don't trust the sellers when it comes to transmissions.
Click to expand...
Core is the transmission case with all the internal parts? Such a shame I could not keep the current Transmission in the car. Thanks for your help.
AbodyBB said:
So having had a time in Germany I have to give you the warning that TUV will scrutinize any welded parts. Your best option would be to find an original K frame with mounts or use the swap mounts they talked about. Not sure if you have to pass TUV but in Germany they were…
If you stay with the 904 transmission all your linkages will work with the V8 transmission. You could even just find a v8 housing and swap the internals over.
Click to expand...
Here in te Netherlands it would be not that hard. When a car becomes 50 years old they don't need you to checked periodical like MOT.(called APK Algemene Periodieke Keuring here). They just assume you are taking care of it as its an Oldtimer. I only have to let them note that i now have 8 in stead of 6 cilinders.
So if I keep the Slant 6 K frame i got in the car i need to weld the conversion mounts like the Schumacker versions. you dont bolt them to the current mounts?
And if i can find a 904 transmission housing for a V8 the current internals of the I6 Housing will fit and handle the power of a 318.
Don't think it will work on a 340/360 i think...?
Want to thank you as well! And everybody that replied to the thread.

Hear me talking. I don't own the car yet and im already making plans of changing it...
 
I think only one side of the part of the mount that is part of the k frame is actually different. One side is the same /6 or V8. But if you can find a set of the Schumacher mounts I'm 98% sure a v8 is a bolt in on the /6 k frame. No welding needed
I mentioned in my post earlier this thread that you'd have to find a different transmission
No a core is a used "takeout" that you then rebuild. Usually a whole complete transmission. What you're talking about is just the outer case/ housing. When we say " core to rebuild" it's just a used transmission.
 
Like this one
www.engine-swaps.com

'67-72 A-Body Slant 6 to 273/318 or 340/360

Uniquely engineered mounting brackets bolt a 273/318 or 340/360 directly to your Slant 6 K-member with no cutting, welding, suspension changes, or K-member removal. Complete kit includes powdercoated brackets, factory style rubber insulators, grade 8 hardware kit, and instructions. Works with...
www.engine-swaps.com
 
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