I'm looking for three measurements, if anyone has access to a stripped '71 Demon. The factory frame dimension charts use the centerline of the axles together with the K-frame as a datum to take the dimensions from. But if your car has no axles or K-frame then those dimensions are no help.
Does anyone have a Demon skeleton laying around?
- Thread starter tom999w
- Start date
-
Two of the three dims I need are in the picture below. If someone could put a stick on their roof and measure from the stick down to the middile of the radiator support (the middle because the radiator support has a slight upward bow in it at the middle). And also another measurement from the bottom of the rocker (not from the bottom of the rocker spotwelded seam, see picture) to the bottom of the radiator support.
Last edited:
Woods74
Enlightened Senior
Body tolerances were loose, some can be 1/2" off or more back when they were making these pop cans.
Enquire about thrust angle correction.
The ones I've done, the passenger spring needs to be shimmed forward to square up the wheel dimensions. This affects the god number, tracking straight is key.
Enquire about thrust angle correction.
The ones I've done, the passenger spring needs to be shimmed forward to square up the wheel dimensions. This affects the god number, tracking straight is key.
@Oldmanmopar probably has those measurements.
Ya, the first screenshot of the factory dimensions above say that the measurements should be within 1/4", haha... I'm not a body guy, but I think 1/4" tolerance in a factory manual is a hell of alot of slop.
A lot of years ago I bought a piece of rear trim for a 70 Challenger. It was NOS from a stealership and it was the piece that goes from one side to the other just above the taillights. It was a 1/4" too long but it fit my ragtop 70 Challenger perfectly. That's when I started looking for body damage and....could not find any. It was my first foray into factory body dimension tolerances.
Kendog 170
Let the boy go !
I think my Ragtop was built on a Monday or Friday. Struggled each time I lined up the driver's door. I don't think it's been hit but I would love to get it on a frame machine and measure things out.
340sFastback
Well-Known Member
I would mount doors, fenders, hood and use those to gauge body alignment. When I removed floor and trans cross member when replacing full floor I made sure doors and body gaps didn't move. With my full floor and trans cross member removed the body was able to flex twist to the point doors would not even close.
Many times I offered to help him with parts and knowledge. He declined. He don't live far from me and bought the car out of a salvage yard down the road for $800. I know that car and it is really in bad shape . The worse I have seen and I declined to buy it several years ago.
The 72 Duster sitting next to it from that swamp land came here after someone bought it for parts and had to find somewhere to dump it. It was complete and we couldn't even get the distributor out with a slide hammer. That should give you an Idea of the rust on the cars from that yard. The only thing that was saved was the tail lights because they were plastic.
You can't help someone who doesn't want it, so I am out
Last edited:
Yes, that's next on the list to do. The plan is to get the front end within factory tolerances, and then temporarily mount the door, hood and fenders to inspect and close up the gaps so they at least look uniform. I didn't think a body could twist that much for a door to not close, although I did weld a brace into the door frame, that's definately something to take into account..
Last edited:
I remember my dad jacking up a car with a bumper jack and you couldn't open the driver's door once it was up. The car was a daily driver and complete.
Would you be interested in complete k member for this?
Yeah, that's not true about the centerline of the axles. You can establish the "O-line" using the rear spring hangers and the front frame rails. From there, you DO need the K member installed. But you absolutely need that to do the work you're doing anyway.
The measurements you want are using the body, and quite frankly the body tolerances on these cars were too loose to be using to them locate your frame members. That's why the factory doesn't have any body to body measurements listed! They're not good enough to set your suspension points up.
All the measurements you want establish the vertical position of the front frame rails. To do that correctly, you need to establish the measurements highlighted here. Put the frame rails and K frame where they need to be and the radiator support will take care of itself.
It looks like I may need a K member, but Owasso is 2.1 million miles away from upstate New York.
Yes, I need those three measurements, if you can get them.
Yes, I agree totally. But right now because the firewall is rusted out, I can literally move the radiator support up and down a foot! That makes sense about not using the body for dims but because of the great movement of the front I need to be able to establish a rough point to start from and then hone in from there. Right now the dimensions are not even in the ballpark.
But if the firewall is rusted out, how do you even know if the cowl is in the right spot to begin with?
And then you have to make sure that you can duplicate the measurement. I mean I have a Duster sitting in my garage, but it doesn't sit level when it's on its wheels. So if I grab a measurement with a bubble level to get the cowl to upper radiator support measurement without leveling my car the same way you've leveled yours it won't be something you can reproduce and it won’t be accurate otherwise.
I’m sure you know this, but you have a TON of work there. Being able to duplicate the factory chassis measurements is the bare minimum for being successful. That’s the starting point. Body fits have to be secondary to that.
You have to establish that “o-line”, and that might mean a lot of work to get the frame rails and K frame to that point.
Honestly, that car should be on a frame table. At the minimum it should be on a flat/leveled surface so you can use a plumb bob and project measurement lines. There really isn’t anything there that you can just assume is in the right spot.
I have a couple skeletons in my closet , but can't talk about them here ! 
All good info, thanks; but I already planned the baseline for the requested measurements, not off of being level, but off of the factory body lines themselves. For example, I laid a stick on the roof and then brought that line forward to the rad support. So the car can be on a hill and I'd still get the same dimension. The same with the other two measurements too. For the cowl line and rocker line, I wasn't leveling anything, I was only continuing the factory lines forward! So all these lines should be the same on all cars, especially since the factory manual says that tolerances of 1/4" is ok.
NC Engine Builder
Grumpy Old Man
- Joined
- Oct 10, 2008
- Messages
- 7,244
- Reaction score
- 12,239
I admire your desire to rebuild some absolutely beyond reason, but you are going to have serious problems if you dont at least put that thing on a flat concrete pad. You CANNOT do what your attempting on dirt with cinder blocks for jack stands. You probably have allready welded twist into the chassis by welding your rockers on with it sitting like that.
-
Similar threads
