Installing front sub frame rail
If you really want to do this, you need to be smart about it. Take lots of measurements for starters. I would recommend removing the engine, and transmission, front suspension and use a bare empty K frame as part of your jig.
Now for a possible part of the problem. K frames are jig weld assembled in a fixture and ALL of them are exact at all 4 points so any 67-76 A body K frame will swap to any 67-76 A body. These are held on with shouldered bolts that locate it EXACT on 4 points. If your K frame is bent from the fender bender I would NOT use it to line up your new framerail. Your better off using a known straight K frame for that. The 2 shouldered K frame bolts, Theres your 2 points to get the rail square.
First thing you want to do go buy 4 cheap magnetic spirit levels. I got mine from Northern Tool for about $2 each. Remove your trunk mat, and door sill plates on both doors. Get the car jacked and level on 4 points. Your concrete floor is not dead level, so you have to make sure the car is. Put one spirit level on each rocker in each door opening facing front to back, one in the trunk across the the transition pan above where the the shock bolts are facing side to side, and one across the upper radiator support on the lip by the radiator top tank facing side to side.
If your replacing the inner fender along with the framerail either temp weld or make and install temporary bolt on supports from the firewall to the radiator support before any removal to keep everything lined up. I recommend removing the inner fender from the replacement rail, then install the replacement rail, then install the inner fender second. It will be difficult to line it up as a complete assembly. Car in the pix has jack stands under the rear axle that are shimmed to make the bubble level in the back level from side to side. Jack stands in the front are on the torsion bar crossmember, and shimmed with thin aluminum shims to make the door opening sills on the rockers level and radiator support level.
The inner fender also has 5/16" diameter alignment holes at top front and top rear to line it up at the back and front. Use 5/16" diameter flat bottom punches to line them up before clamping and welding. Check every measurement multiple times before buzzing it together.
Remember that the whole car is nothing but alignment holes. Last pic if looking straight down through the holes that have body plugs in them in the trunk floor and transition pan. There are corresponding holes lined up at the bottom of every LH and RH framerail in these same spots. This is where the framerails were set down into an assembly line jig with multiple steel pins sticking up. The floor pan sheetmetal was then set down onto the same pins over top of the framerails and clamped together. Then workers proceded to pinch it all together with spot welders at the factory. Remember they made 275,000 dodge darts in just 1969 this doesnt include the number of valiants and barracudas in this same year. This is a lot of effing cars. This stuff had to have ways to fit it together on the assembly line quickly and accurately especially in regards to suspension and K frame locating.
Hope this helps you out. Best of luck.
If you really want to do this, you need to be smart about it. Take lots of measurements for starters. I would recommend removing the engine, and transmission, front suspension and use a bare empty K frame as part of your jig.
Now for a possible part of the problem. K frames are jig weld assembled in a fixture and ALL of them are exact at all 4 points so any 67-76 A body K frame will swap to any 67-76 A body. These are held on with shouldered bolts that locate it EXACT on 4 points. If your K frame is bent from the fender bender I would NOT use it to line up your new framerail. Your better off using a known straight K frame for that. The 2 shouldered K frame bolts, Theres your 2 points to get the rail square.
First thing you want to do go buy 4 cheap magnetic spirit levels. I got mine from Northern Tool for about $2 each. Remove your trunk mat, and door sill plates on both doors. Get the car jacked and level on 4 points. Your concrete floor is not dead level, so you have to make sure the car is. Put one spirit level on each rocker in each door opening facing front to back, one in the trunk across the the transition pan above where the the shock bolts are facing side to side, and one across the upper radiator support on the lip by the radiator top tank facing side to side.
If your replacing the inner fender along with the framerail either temp weld or make and install temporary bolt on supports from the firewall to the radiator support before any removal to keep everything lined up. I recommend removing the inner fender from the replacement rail, then install the replacement rail, then install the inner fender second. It will be difficult to line it up as a complete assembly. Car in the pix has jack stands under the rear axle that are shimmed to make the bubble level in the back level from side to side. Jack stands in the front are on the torsion bar crossmember, and shimmed with thin aluminum shims to make the door opening sills on the rockers level and radiator support level.
The inner fender also has 5/16" diameter alignment holes at top front and top rear to line it up at the back and front. Use 5/16" diameter flat bottom punches to line them up before clamping and welding. Check every measurement multiple times before buzzing it together.
Remember that the whole car is nothing but alignment holes. Last pic if looking straight down through the holes that have body plugs in them in the trunk floor and transition pan. There are corresponding holes lined up at the bottom of every LH and RH framerail in these same spots. This is where the framerails were set down into an assembly line jig with multiple steel pins sticking up. The floor pan sheetmetal was then set down onto the same pins over top of the framerails and clamped together. Then workers proceded to pinch it all together with spot welders at the factory. Remember they made 275,000 dodge darts in just 1969 this doesnt include the number of valiants and barracudas in this same year. This is a lot of effing cars. This stuff had to have ways to fit it together on the assembly line quickly and accurately especially in regards to suspension and K frame locating.
Hope this helps you out. Best of luck.
