How Do J Bodies compare to M Bodies?

randomguy

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Hello all, long time. Anyways, long story short I've been thinking somewhere down the line picking up an 80-83 J-Body with a 318 or 360 (maybe) or maybe very late 88 or 89 Fifth Ave to drive on occasion to errands. Anyways, in the past I owned a sweet 84 Chrysler Fifth Avenue and miss the seats in that car and how quiet it other than a little burble.

With that in mind, I'm wondering how the J-Body drives compared to say an M-Body like the 5th Ave and I'm wondering how do the seats and comfort compare? Thank you in advance.
 

BudW

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Any year M body will be easier to find parts for than a J-body (like quarter extensions, windshields and door handles, for example).
I like the J-bodies more, but with 9 year old twins - the M-body makes more sense in my case
 

kkritsilas

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The only year that a 360 came in a factory J body was 1980. There were 68 (I think) 360 J bodied Miradas from memory (please feel free to correct me if my memory is faulty). I don't know how many Cordobas had 360s. So you will probably only see 318 V8s, unless you have a modified car (which can have 360s, Big Blocks, or Gen III Hemis). In most of the US, the 318s were 2 barrels for everywhere outside of California and in high altitude areas; in California and high altitude areas, 318 4 Barrels were available. Canadian J bodies had either available. Factory cars were all automatics (A904 (i.e. the "small" Torqueflite) family, either A904, A998, or A999, the 360 cars had A727 (i.e. the "big" Torqueflite)) all 3 speeds. Modified cars can pretty much have anything in terms of transmission. There are also slant 6 cylinder J bodies, which by all accounts are quite enjoyable to drive. Chassis wise, the J body is built on the same chassis as the 4 door M body. I cannot say how the driving between the J body and M body compare, as I don't have an M body.
 

BudW

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Chassis wise, the J body is built on the same chassis as the 4 door M body.
F and M bodies (2 and 4 door being in separate classes) are fairly close, chassis wise.
J body are (I’m guessing) 2/5th the same chassis as F and M bodies.

I think the only part chassis wise is frame rails (note: J’s do not have bumper shocks where as all F and M’s do have - so could be wrong), K-frame, firewall (could be wrong here) and floorboard (could be wrong here too).
The transmission crossmember is way different.

The only thing I know is the same is K-frame, suspension systems and powertrain.

BudW
 

Buck Atwater

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I'm a big J body fan, but in my experience Fifth Avenues and Diplomats are a lot tighter in the squeaks and rattles department. Being sedans, there is less body flex and the doors actually have window tracks unlike J bodies which just have the regulator on a stick that allows to the glass to rattle and sound like crap when you close the door lol.

As for seats I find the vinyl buckets in my Mirada quite comfortable, but it's hard to beat those couch like tuffed seats in a 5th avenue too.
 

Justwondering

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Buck -
I had to laugh when you described the door sounds.
I've been reconditioning my 87 fifth avenue, learning as I go.
Last week I drove it about 16 miles and and I swear every window was rattling and two of them would only go down and not up. No squeaks, just rattles.

A new project. lol
 

BudW

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My first car was a ’77 Cordoba (door glass mechanism is very much like the 2 door FMJ cars). In ’85 I was able to grab ahold of the top of door glass and could pull it outwards enough for a person to stick their (skinny) arm in to unlock the car door. My arms were a lot thicker back then. It was a two person job to do, but could be done - or solo if you had a coat hanger.


Justwondering, get with me about the down but not up, and rattle concerns.

BudW
 

Justwondering

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Buddie..
will get with you on the windows but after I finish the frankantenna project .. lol
 

randomguy

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Thank for the responses thus far. I am throwing some ideas around and was thinking of things. I will start a new post here for some more questions in another thread.
 
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