71 demon

[maldridgeks]

Hello everyone. I am considering acquiring a 1971 demon. It is supposedly all original with 318/727 but with a 7.25 rear end. A few questions for you.

1. Any idea how costly to upgrade rear end? Or unnecessary with the 318?

2. Easiest way to confirm it’s a real demon?

3. Does the engine/tranny/rear diff combo seem feasible from factory?

Thank you.

 

[413]

How are you going to drive it, how much power?
Cruise around or beat on it? A body 8 3/4 is minus $700 and up depending on gears, SG, and complete condition.

LM29 VIN, A fastback dart is a demon, they have unique tail lights and rear panel. It's either a demon or a duster.

Are you sure it's a 727? Should be a 904. Yes that's common with small rear axle.

Does it have a fender tag or broadcast sheet?

 

[maldridgeks]

Thank you. We were hoping to get one that would be an easy swap to a 340 or 360. But absent that, I assume 7.25 would be fine behind a stock 318?

I’ve not seen the trans but seller is a mechanic and a mopar guy, so I assume he knows the difference. I will be getting some pics of underside soon, so I can confirm myself.

It does have fender tag.

 

[AJ/FormS]

I have never seen a Demon that wasn't a real Demon.
If it's not a Demon, then it must be something else. Is there even such a thing as a fake Demon?
Now
a Demon 340, yeah, those can be faked, but it's still gunna be a real Demon, lol.

If the 7.25 has a Limited Slip, and you do not run fat tires nor a clutch, then it can last many miles maybe years back there. I've run them behind hot 318s and even one 340, in the which the A904 died first.

 

[Syleng1]

If factory 318- then 8-3/4 rear was standard. Okay- all the Demons I owned that were v-8’s were 8-3/4.
The slant six cars were 7-1/4”
But somebody on here that knew a guy that was related to a guy on the second shift at Chrysler will say otherwise. lol!
I do not recommend a 7-1/4 regardless of anything bigger than a slant six.

 

[413]

I had a 318/904 demon with 7.25, backed up by the broadcast sheet. Guys dad was original owner, no monkey business going on with parts swapping.

 

[72bluNblu]

I have never seen a Demon that wasn't a real Demon.
If it's not a Demon, then it must be something else. Is there even such a thing as a fake Demon?
Now
a Demon 340, yeah, those can be faked, but it's still gunna be a real Demon, lol.

lol! There’s gotta be at least half a dozen Dusters that have entirely Demon bodywork just on FABO alone. My Duster has all Demon exterior bodywork. It’s not even a ‘71 or ‘72, and despite my not really trying to make it an accurate clone it’s still only a few pieces away from only being able to tell the difference from the VIN #’s.

It’s not unusual at all to clone a Duster or a later Dart Sport into a Demon. The Demons are more popular and Duster and Dart Sport production numbers were far greater. Like over 50x if you consider the whole production run ‘70-‘76.

If factory 318- then 8-3/4 rear was standard. Okay- all the Demons I owned that were v-8’s were 8-3/4.
The slant six cars were 7-1/4”
But somebody on here that knew a guy that was related to a guy on the second shift at Chrysler will say otherwise. lol!
I do not recommend a 7-1/4 regardless of anything bigger than a slant six.

No, factory 318/auto cars had 7.25’s standard. Many of them did have 8.75’s, but they definitely could and did come with 7.25’s.

 

[Oldmanmopar]

Most all 318/auto cars have 7 1/4's.

I have had plenty of factory 318, 904, 7 1/4's I have never seen a 318 , 727, with a 7 1/4. More then likely the 904 was swapped out with a 727. I have seen 904's with 8 3/4's behind them. I had a 69 Dart GT 318 , 904 with a suregrip ordered new. and a couple 68 Dart GT's with trac-locks . But Never a 727 with a 7 1/4 in any mopar from the factory. Show me the Data plate.

I have tons of linkage, the later 318 4 bbls had 904's and the throttle pressure linkage is a hard item to find. late 77-79 F-body Police car only.

A Demon with a 318 2bbl a 727 and a 7 1/4 factory original? I don't think so. It would need B or C-body 318 2bbl 727 3 piece throttle pressure linkage to make it work. Demons were only available with a 727 in a 340 car .

 

[maldridgeks]

I received additional photos. Indeed it is a 904 not a 727.

 

[transman]

With the VIN, it is real easy to determine what the car came with from the factory. Like others, I've seen Demons that didn't have the 340. Post the vin here and let's see what the vehicle came with.