Frame swaps

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*This subject comes up often to a rodder who wanted to improve the ride, braking and handling characteristics of his 1949 International KB2 pickup truck. Many of the points made here will apply to other frame swaps as well. This article is actually more about a front/rear frame clip swap rather than using the entire frame intact.  
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*This subject comes up often and I originally wrote this wiki article for a rodder who wanted to improve the ride, braking and handling characteristics of his 1949 International KB2 pickup truck. Many of the points made here will apply to other frame swaps as well. This article is actually more about a front/rear frame clip swap rather than using the entire frame intact.  
  
  
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I like the Gen I because of the fairly narrow track, 60.7" front and 59.5" rear. Everything got wider in the Gen II truck and may present some problems with track width with the International. Well, not problems really, but the tires might stick out too far and you'd have to use different wheels with a different off-set or fender flares or some other such foolishness that can be avoided by using the narrower track Gen I in the first place. Depending on the configuration of the Gen I Dakota, three different wheelbases were used, 112.0", 124.0" and 131.0. By the way, these trucks came with power rack and pinion steering.  Another thing of interest is that these trucks came in 2WD and 4WD. So, if you wanted a 4WD International, you could certainly have it. Before removing any parts from the Dakota donor, roll it onto a scale and weigh just the front axle weight. Write it down. Now, weigh just the rear axle weight. Write it down. You will need this information later if you need to change springs.
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I like the Gen I because of the fairly narrow track, 60.7" front and 59.5" rear. Everything got wider in the Gen II truck and may present some problems with track width with the International fenders. Well, not problems really, but the tires might stick out too far and you'd have to use different wheels with a different off-set or fender flares or some other such foolishness that can be avoided by using the narrower track Gen I components in the first place. Depending on the configuration of the Gen I Dakota, three different wheelbases were used, 112.0", 124.0" and 131.0. By the way, these trucks came with power rack and pinion steering.  Another thing of interest is that these trucks came in 2WD and 4WD. So, if you wanted a 4WD International, you could certainly have it. Before removing any parts from the Dakota donor, roll it onto a scale and weigh just the front axle weight. Write it down. Now, weigh just the rear axle weight. Write it down. You will need this information later if you need to change springs.
 
   
 
   
  
If a guy were going to use the entire frame intact, he might get lucky and find that one of these 3 different wheelbases were exactly right for the International. If not, use the Dakota frame that has a longer wheelbase than the International and section the frame between the cab and differential, then have the drive shaft shortened or order a custom drive shaft. For getting the wheels/tires just right in the wheel wells for the best look, I'd jack up the International, remove the wheels and tires, then lower the body back to the ride height I wanted to use and place jack stands under the frame. I'd roll the front and rear tires forward and backward in the wheel wells until I got the "eyeball" that I wanted and measure the wheelbase between the centers of the wheels. That's the figure I would use for the final wheelbase to build the truck on. Once I got the eyeball right, I might drop a line on a plumbob from the center of the wheel to the ground and make a mark. Drop a line from some point on the body and make a mark. Measure between the points and write it down. Do this front and rear. Take the measurement off the BODY, not the fender or the bed. You'll need this info later to position the front and rear Dakota clips if you decide to build the truck lower than stock. Having done this insanity for 50 years, I have determined that you don't want any part of the truck lower than 4.000" from the ground when measured at curb weight(ready to drive and with a 1/2 tank of gas), so don't go nuts with the positioning of the body. I have found that keeping a 4x4 piece of timber handy to scoot around under the truck during the build will insure that you have sufficient ground clearance to miss most road obstacles.
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If a guy were going to use the entire frame intact, he might get lucky and find that one of these 3 different wheelbases were exactly right for the International. If not, use the Dakota frame that has a longer wheelbase than the International and section the frame between the cab and differential, then have the drive shaft shortened or order a custom drive shaft. For getting the wheels/tires just right in the wheel wells for the best look, I'd jack up the International, remove the wheels and tires, then lower the body back to the ride height I wanted to use and place jack stands under the frame. I'd roll the front and rear tires forward and backward in the wheel wells until I got the "eyeball" that I wanted and measure the wheelbase between the centers of the wheels. That's the figure I would use for the final wheelbase to build the truck on. Once I got the eyeball right, I might drop a line on a plumbob from the center of the wheel to the ground and make a mark. Drop a line from some point on the body and make a mark. Measure between the points and write it down. Do this front and rear. Take the measurement off the CAB, not the fender or the bed. You'll need this info later to position the front and rear Dakota clips if you decide to build the truck lower than stock. Having done this insanity for 50 years, I have determined that you don't want any part of the truck lower than 4.000" from the ground when measured at curb weight(ready to drive and with a 1/2 tank of gas), so don't go nuts with the positioning of the body. I have found that keeping a 4x4 piece of timber handy to scoot around under the truck during the build will insure that you have sufficient ground clearance to miss most road obstacles and allow enough suspension movement to afford a good ride.
 
   
 
   
  
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Here's how I might do the "lower than stock" build.  
 
Here's how I might do the "lower than stock" build.  
With your Dakota donor truck still complete and sitting level, put an inclinometer on the lower control arms and write down the angle. (assuming you're using a 2-wheel drive donor). This will insure that when the International is finished, the angle of the Dakota lower control arms will be the same as they were stock and all the suspension geometry will be stock. Use the inclinometer on some part of the frame or spring hat or upper control arm mounting points inside the engine compartment to find the fore-aft angle of the front of the frame. You'll need this information later when you mate the Dakota clip to the International center section to make certain the clip is the same as stock so that you don't screw up the caster that's engineered into the front suspension. Write it down. With the Dakota front clip cut off at the firewall and sitting loose, disassemble and remove the torsion bars and shocks. Re-assemble without the bars using All-thread, washers, nuts and whatever it takes to put the All-thread in where the shocks mounted to hold the whole mess together without the torsion bars and at the control arm angle you found when you put the inclinometer on the lower control arms of the Dakota when the truck was complete. Chock up the Dakota clip at the fore-aft attitude you found with the inclinometer in the engine compartment of the Dakota when it was still complete. With the International cab and center frame clip positioned at the height and attitude you want as a finished product, roll the Dakota clip into place and connect the Dakota clip to the International middle frame section. Use your gas axe to cut pieces off the Dakota/International frame clips where they interfere with each other as you roll the Dakota frame clip into position. Position the center of the front wheel of the Dakota clip relative to the International body using the dimension you wrote down when you originally dropped a line from the body. Of course, you'll want to fish-plate the connections you make at the Dakota/International frame connection to assure integrity of the graft. The resulting connection might look somewhat like a "Z" as viewed from the side. This is called Z-ing the frame.
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With your Dakota donor truck still complete and sitting level, put an inclinometer on the lower control arms and write down the angle. (assuming you're using a 2-wheel drive donor). This will insure that when the International is finished, the angle of the Dakota lower control arms will be the same as they were stock and all the suspension geometry will be stock. Use the inclinometer on some part of the frame or spring hat or upper control arm mounting points inside the engine compartment to find the fore-aft angle of the front of the frame. (THIS IS WITH THE DAKOTA DONOR TRUCK STILL ALL TOGETHER AND SITTING SQUARE ON A LEVEL SURFACE WITH TIRE PRESSURE EQUALIZED AT MFG SPECS). You'll need this information later when you mate the Dakota clip to the International center section to make certain the clip is on the same fore/aft attitude as stock so that you don't screw up the caster that's engineered into the front suspension. Write it down. You want to adjust the caster so that the steering wheel comes back to neutral all by itself after a turn and in order to achieve that, the clip must be installed at the same angle it was in the donor truck. If you're doing the project with just the clips that you found or purchased, find a complete, running Dakota that the owner will let you take some angles from, again, with the truck sitting on a level surface and tires aired up. With the Dakota front clip cut off at the firewall and sitting loose, disassemble and remove the torsion bars and shocks. Re-assemble without the torsion bars using All-thread, washers, nuts and whatever it takes to put the All-thread in where the shocks mounted to hold the whole mess together without the torsion bars and at the control arm angle you found when you put the inclinometer on the lower control arms of the Dakota when the truck was complete. This is where you will make or break the project, getting the clip at the proper attitude and spindles positioned at the same place relative to the Dakota frame section. Chock up the Dakota clip at the fore-aft attitude you found with the inclinometer in the engine compartment of the Dakota when it was still complete. With the International cab and center frame clip positioned at the height and attitude you want as a finished product, roll the Dakota clip into place and connect the Dakota clip to the International middle frame section. Use your gas axe to cut pieces off the Dakota/International frame clips where they interfere with each other as you roll the Dakota frame clip into position. Position the center of the front wheel of the Dakota clip relative to the International body using the dimension you wrote down when you originally dropped a line from the body. Of course, you'll want to fish-plate the connections you make at the Dakota/International frame connection to assure integrity of the graft. The resulting connection might look somewhat like a "Z" as viewed from the side. This is called Z-ing the frame.
 
   
 
   
  
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If I were looking for a donor like this, I might try finding a truck with a fragged motor and/or transmission to make the purchase price more attractive. The one thing that would be MANDATORY in my opinion, would be a clear Carfax. You don't want to start with a frame that's been tweaked in an accident. I might even take a tape with me to go look at it before the purchase, crawl under and measure on an "X" between points underneath to insure that the frame if square.
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If I were looking for a donor like this, I might try finding a truck with a fragged motor and/or transmission to make the purchase price more attractive. The one thing that would be MANDATORY in my opinion, would be a clear Carfax. You don't want to start with a frame that's been tweaked in an accident. I might even take a tape with me to go look at it before the purchase, crawl under and measure on an "X" between points underneath to insure that the frame is square.
 
   
 
   
  
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With the Dodge on a level, flat pad, put jackstands under the frame just behind the firewall and just ahead of the spring arch in the rear just so that the tires are barely off the ground. Take measurements from the firewall to the location of the hood latch on the core support. Remove the hood and fenders. Leaving about 8-10 inches of frame stub in front of the firewall, torch off the front frame clip. Go to the rear and torch off the rear frame clip, leaving enough stub so that you can weld the Dakota rear clip onto it.  
 
With the Dodge on a level, flat pad, put jackstands under the frame just behind the firewall and just ahead of the spring arch in the rear just so that the tires are barely off the ground. Take measurements from the firewall to the location of the hood latch on the core support. Remove the hood and fenders. Leaving about 8-10 inches of frame stub in front of the firewall, torch off the front frame clip. Go to the rear and torch off the rear frame clip, leaving enough stub so that you can weld the Dakota rear clip onto it.  
  
Now, drop the body down to exactly where you want it for ride height and level it side to side. If you want a little California rake to it, then position the body for a little rake. If you want the body to be level, then position it level, with whatever ground clearance you want. If you want the back lower than the front like a liquored-up Kentucky hillbilly, then position the body that way. What we're doing here is getting the exact ride height and body attitude we want without the use of Fosdick dropped spindles or cut spring coils or any other amateurish monkey business. It'll be all stock with the Dakota ride quality and Dakota steering geometry and Dakota brakes. Cool, huh?
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Now, drop the body down to exactly where you want it for ride height and level it side to side. If you want a little California rake to it, then position the body for a little rake. If you want the body to be level, then position it level, with whatever ground clearance you want (You do have a 4x4 piece of lumber don't you?). If you want the back lower than the front like a liquored-up Kentucky hillbilly, then position the body that way. What we're doing here is getting the exact ride height and body attitude we want without the use of Fosdick dropped spindles or cut spring coils or any other amateurish monkey business. It'll be all stock with the Dakota ride quality and Dakota steering geometry and Dakota brakes. Cool, huh?
  
Now, with the Dakota chassis secured at stock Dakota ride height, just like in a real, running example of the truck, mount the motor and transmission into the chassis on the stock mounts. At the engine crossmember, fabricate a caster wheel (pirate one off a derelict shopping cart or whatever) and attach it under the crossmember, having the caster wheel touch the ground and located slightly to the rear of the Dakota wheels and tires, so that you have a short tricycle. Cut the Dakota front frame clip off the chassis right behind the transmission crossmember. You want to keep the forward/rearward tilt of the front clip in the same position as it was on the Dakota chassis at ride height. If you allow the clip to tilt forward or backward from the factory-designed attitude, trust me, nothing will work properly. Been there, done that. PAY ATTENTION. That's why I use the third wheel and make a tricycle out of it, to keep everything like it's supposed to be.  
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Now, with the Dakota chassis secured at stock Dakota ride height, just like in a real, running example of the truck, mount the motor and transmission into the chassis on the stock mounts (you'll want to use new insulators while you're at it). At the engine crossmember, fabricate a caster wheel (pirate one off a derelict shopping cart or whatever) and attach it under the crossmember, having the caster wheel touch the ground and located slightly to the rear of the Dakota wheels and tires, so that you have a short tricycle. Cut the Dakota front frame clip off the chassis right behind the transmission crossmember. You want to keep the forward/rearward tilt of the front clip in the same position as it was on the Dakota chassis at ride height. If you allow the clip to tilt forward or backward from the factory-designed attitude, trust me, nothing will work properly. Been there, done that. PAY ATTENTION. That's why I'd use the third wheel and make a tricycle out of it, to keep everything like it's supposed to be for stock attitude and angles.  
  
As you move the Dakota front clip into position in the front of the Dodge, you may have to cut the transmission crossmember off and some more of the frame ahead of the crossmember, depending on what's in the way of letting you push the clip back far enough to get the motor up against the firewall. If you have to do this and the transmission wants to dangle, put the trans pan on a creeper and chock it back up to the proper height with wood blocks so you can still roll the Dakota front clip around. Make certain you put a level on the Dakota clip to insure it's not lower on one side than the other. If it's out a little, you can add or let a little air out of one tire to level it up. You will have to trim each of the two Dodge frame stubs and each of the two Dakota clip stubs as you move the Dakota clip into position. Just keep trimming and moving and measuring for equal wheelbase side to side until you get it there and you see how you are going to join the stubs together. You can be measuring from holes in the frame on the Dodge and the Dakota that you know are the same distance left to right in order to keep the wheelbase equal. Once you feel like you're close, have a couple of buddies hold one of the front fenders in position so you can eyeball the car from the side and check the position of the tire in the wheelwell. This is where you want to PAY ATTENTION, as this relationship will make or break the swap. Once you have the clip in place, make up your 2" x 4" "Z" components to join the stubs together. Tack them in place for now, you can finish welding them later and add flat "fish plate" reinforcements to the sides of the joints. You may have to make minor changes, so don't finish weld until you know that everything is absolute right.  
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As you move the Dakota front clip into position in the front of the Dodge, you may have to cut the transmission crossmember off and some more of the frame ahead of the crossmember, depending on what's in the way of letting you push the clip back far enough to get the motor up against the firewall. If you have to do this and the transmission wants to dangle, put the trans pan on a creeper and chock it back up to the proper height with wood blocks so you can still roll the Dakota front clip around. Make certain you put a level on the Dakota clip to insure it's not lower on one side than the other. If it's out a little, you can add or let a little air out of one tire to level it up. You will have to trim each of the two Dodge frame stubs and each of the two Dakota clip stubs as you move the Dakota clip into position. Just keep trimming and moving and measuring for equal wheelbase side to side until you get it there and you see how you are going to join the stubs together. You can be measuring from holes in the frame on the Dodge and the Dakota that you know are the same distance left to right in order to keep the wheelbase equal. Once you feel like you're close, have a couple of buddies hold one of the front fenders in position so you can eyeball the car from the side and check the position of the tire in the wheelwell. This is where you want to PAY ATTENTION, as this relationship will make or break the swap. Once you have the clip in place, make up your 2" x 4" "Z" components to join the stubs together. Tack them in place for now, you can finish welding them later and add flat "fish plate" reinforcements to the sides of the joints. You may have to make minor changes, so don't finish weld until you know that everything is absolute right. Having the motor/trans installed in the Dakota clip will allow you to bolt the headers up and cut the Dodge sheetmetal and other things that get in the way of the headers. MAKE THE HEADERS FIT WITH NO INTERFERENCE, THEN USE SCRAP METAL TO FILL IN THE HOLES OR DIVOTS THAT YOU HAD TO MAKE TO CLEAR THE HEADERS. NEVER LET ANYTHING GET IN THE WAY OF INSTALLING A GOOD SET OF TUNED, LONG-TUBE HEADERS. 
  
 
Do the same with the rear, making a tricycle with a caster wheel so that you can just wheel the clip up into place, same way you did in front.
 
Do the same with the rear, making a tricycle with a caster wheel so that you can just wheel the clip up into place, same way you did in front.

Revision as of 13:00, 18 October 2011

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