Frame rail and main structure measurements

[mopar4don]

Correct. It's not the hole for the bolt but rather the back edge of square tube that measures 12 3/4" to the datum line.

What about the rear mount? Is the rear frame rail flat or does it have a slope?
Did you subtract the distance from the bottom of the rail to the center of the shackle pin from the "J" dimension or 16 7/8?

I REALLY APPRECIATE the help! :hello2:

 

[5wndwcpe]

If memory serves, the rear frame is (or nearly is) parallel to the datum line. Here I cheated a little and set the car down on the other six mounts, raised/lowered the rear of the car as needed to get the 16 7/8" measurement (center spring shackle to datum) and then made the rear mount to whatever it needed to be. As you so noted, there is no reference on the frame spec sheet for the hole I used so I had to improvise.

 

[Dodge33]

hello you guys, this is a very helpfull thread, here at the shop
we are buildind a frame jig,doing a a-body convert,we are
making the jig adjustable to also do our b-body cars. I WILL
be reading this thread to get idea's and such.

 

[hunt2elk]

Any updates Don? I am curious as to what you have found out. I took measurements of mine before bracing for the metal replacement and with a bare shell like you have. Mine was fairly square and level in this state, well within specs at least.

 

[mopar4don]

Hi Elk,
I ended up lifting the rear of the car to get the front dimension. I mounted the front at the forward K frame bolt location. Then I lifted the rear to spec. This left the front spring mount dimension a little to much, (plus 3/8). But I can put a C-clamp on it and pull it down. So I think by time I get the car cut up it will relax to all the specs. Thanks to all who helped with this especially 5wndwcpe!
So I guess the next step will be making a resto thread, ....... in the near future.

 

[5wndwcpe]

:tiphat: Glad we could help and keep us posted Don.

 

[Hemirunner]

Excellent thread. My question is "how close is close enough"? I was doing some rough measurements to see how square the car is and my 'X' measurements were 3/8" different from each other. Should I be putting this thing on a frame jig?

 

[5wndwcpe]

Excellent thread. My question is "how close is close enough"? I was doing some rough measurements to see how square the car is and my 'X' measurements were 3/8" different from each other. Should I be putting this thing on a frame jig?

I'm assuming the car is on jack stands so given that, I'd drop a plumb line from several corresponding points on each frame rail and mark them on the floor. If your car is off by 3/8" it should show up elsewhere. If it doesn't, it could be as simple as the frame hole you're using for a reference is in the wrong spot.

If the plumb lines show that the car is racked somewhat, I'd try to determine if it got that way because of an accident or it was welded together crooked at the factory. 3/8" is a huge amount by today's standards but when these cars were slapped together, that was the difference between a Wednesday built car and a Friday built car.

When you asked about putting the car on a frame jig, did you mean a frame machine to straighten it out or a jig to hold it in position while replacing sheetmetal ?

 

[Hemirunner]

The body is on jack stands now and is stripped and gutted. The right rear quarter, trunk pan and rear tail light panel are all out of the car (got it that way). There is evidence of right front damage in the cowl area, can't tell if it was hit or what happened. I measured diagonally from the rear frame to the front frame under the firewall and it seems to be within 1/8 of square by my crude measurements. When I measure diagonally from the front frame under the firewall to the front K member bolts, the measurements differ by 3/8" so I'm assuming that the front frame rails are racked over to the drivers side from whatever caused the right front cowl damage. Maybe it's been on a frame machine and that's as close as they could get it or maybe they measured and figured it was close enough to not bother with it. If I build a jig like yours, I'm assuming that I'd have to remove a bunch of front sheetmetal to get it to straighten up and I'd rather not have to dismantle the front as it's all good and the damaged area has been repaired prior to me getting the car and won't show anyway once done. Maybe a frame machine could bring it back and get it corrected?? I do not have any experience in this area so I don't know what the capabilities of a frame machine are?

 

[Donny]

This is a fantastic information-filled thread! I've built a few of these, but, nowhere near the high level you all have in yours here! This is something I need to emulate, and replicate in/on mine! As I said in my Satellite thread, and I'll say here, I'm taking a BIG step back to make proper and correct steps forward!