Looking for advice on a '71 Demon

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So I've been looking for an A Body for several months now, to pair with my '74 Rallye Challenger and add to my Mopar Collection.

I've come across a '71 Demon that looks to be in very good shape, most importantly the body seems to be in good shape, which will go along way towards putting fresh paint on it.

Here's the catch though, it was an original 6-cylinder car, that has been converted to a 318. The seller also has a 340 to go with the car.

My question is this, is there anything specifically I should look for/be wary of when it comes to a swap like this? My thoughts immediately go to the K-member and wondering if that should have been swapped out going from a 6 cylinder to an 8.

Now admittedly, going to a small block makes me think the original might be sufficient, but I wondered what others thought.
Not to mention, again, if there are other things I should be aware of when/if I go to look at it.

Thanks!!
 
Schumacher creative offers mounts for small block to /6 k member, they work well from my experience, swapping the k frame is of course simple enough too. T bars from /6 will be ok with a small block, brakes are always a concern IMO, as they were often marginal at best from the factory, also not overly complicated. Assuming you are somewhat mechanically inclined as an E body owner already, you shouldn't have any real problems with anything on an A body
 
What rear end is in it? I would give the body a good going over. Some can look great while hiding problems underneath as you are likely already aware. If your paying a high price for it I would posts some detailed picture of it so those more versed in demons can pick it apart so you know what you are buying. I know some put a high value on 340's but I would want to see the heads off and or pan pulled before paying a high price for the package deal.
 
Engine mounting is low on the priority, fully check the car for front upper A-Frame mounts and the usual rust areas. If the frame is solid and body good then go for it. The frame is all the matters and look very closely.
 
I would ask the seller if he put a V8 k-frame in it and from what year. Like said above, you can make modifications to a slant frame and it will work. 340/360 cars have stronger torsion bars and usually disc brakes. The spool mount k-frame from later years is the better frame. 71's had a different set up- biscuit style mounts. You can look at pics on Shumacher's web site to see what's involved in a slant to V-8 swap
 
The V8 K frame is not any stronger than the slant, which it seems like you might believe. The difference is the engine mounts. You can get conversion mounts and keep the existing K or swap to a V8 K if not already done. I prefer to swap them since its not hard to do and they are relatively easy to come by still.
Disc brakes on the car are a plus, power disc even better. I have seen plenty of drum brakes on 340 cars. Rear end is likely a 7 1/4 unless someone special ordered or someone already swapped. Again, 8 3/4 is a big plus and even an 8 1/4 is not a bad rear for light duty street car.
You really have to take a good hard look at the car and see what it has. If things were swapped, see if they were done correctly or just cobbled together.
Rust is always the main concern. Everything else can be tailored to your wants.
 
None of it really matters anymore unless $ is the game. They can pretty much all be fixed. Engine choice mounting would be low on my list though in deciding.
 
Yep, didnt miss that part, but he's talking about a 340 going in. A lot of people dont know that 318 A/C car torsion bars are really stock 340 bars.
 
The V8 K frame is not any stronger than the slant, which it seems like you might believe. The difference is the engine mounts. You can get conversion mounts and keep the existing K or swap to a V8 K if not already done. I prefer to swap them since its not hard to do and they are relatively easy to come by still.
Disc brakes on the car are a plus, power disc even better. I have seen plenty of drum brakes on 340 cars. Rear end is likely a 7 1/4 unless someone special ordered or someone already swapped. Again, 8 3/4 is a big plus and even an 8 1/4 is not a bad rear for light duty street car.
You really have to take a good hard look at the car and see what it has. If things were swapped, see if they were done correctly or just cobbled together.
Rust is always the main concern. Everything else can be tailored to your wants.
Have 340 here that did come with drum brakes.
 
The core support opening might be less than 22", some sixes used a narrower opening. Might affect low speed cooling - run hot in stop & go traffic.
 
Smallest core opening on 67-72 A body is 22". The slanty radiator mount flange on i believe the left side is longer to cover the opening and reach the radiator support threaded mounting holes. 67. 68, 69 383 and 440 A bodies ran a 22" opening when new and seemed fine
 
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Ah, I was thinking of the 73-76 cars. I just drilled out a pile of spot welds for a friend with a 73.

Memory's the first thing to go.
 
Thanks for all the replies guys, all kinds of excellent advice in here.

To an early question, it sounds like the rear end has been replaced. It has the 8 3/4 read end with a 3.91 Sure Grip.

Where are the "trouble spots" body-wise I should look for? I'm going to call the guy over the weekend and see about taking a look.

I'll post some pictures if/when I do.

Thanks again!!
 
Rear leaf spring perches, torsion bar crossmember, floors, both front passenger area and trunk, especially around the spare tire well, inner fenders, sometimes cowl, depending if it came from the rust belt areas.
 
Especially the torsion bar crossmember. See above. And bubbling paint [pre-rust] around the windshield and back window.
 
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