59 to 72 chassis swap

[59 Bitsa]

Hey everyone

I am new to this forum so please forgive me if i make a few mistakes.

I am working on my 59 task force long box fleet. I am thinking about doing a chassis swap. I would like to use the 67-72 pick-up i just find that chassis one of the best ever made for a street driven truck. Ya ya i know there is kits out there for the newer style frames but thats not what i want.

Has anyone ever done this swap and if so was there any major hurdles?
Any help, advise or pics would be great

Thanks

[dsraven]

welcome to a fellow Albertan.
how much do you anticipate that swap costing you? just curious because by the end of the day it may be cheaper to buy a new frame with all the custom stuff done. check out canadian hotrods site, they are in bc, shuswap area.rebuilt genuine corvette underpinnings and nicely done frames. powdercoated and ready for your body to bolt on. hidden brake lines, fuel lines, battery cables etc. a true completely assembled roller. TCI also makes a nice looking frame but with the Canadian dollar the way it is the USA stuff would be pretty spendy.
I am working on a 57 gmc with a 58 chev long box frame. I think I may just put that frame aside and use an envoy frame that I have. it already has the bigger abs brakes, strut front end, all wheel drive, auto o/d, mid frame fuel tank etc etc. my old frame is boxed and mustangII front end installed, ford 8.8 rear posi with 4 link. all set up for air bags. lots of work went in but I think I will go with the envoy anyway. there is a guy on here doing the trailblazer/envoy swap. here is his build thread
http://67-72chevytrucks.com/vboard/s...d.php?t=515876
I have heard the era of truck you plan to use is a pretty good fit. some will say stick with the original frame because it is made for your truck. it is a personal preference but be aware it is as much work to swap as it is to upgrade the stock frame. consider what you plan on using for power and decide what you need for upgrades to the other frame as well, if anything. do you have the new frame? does it need a rebuild of suspension, brakes, diff etc? post up some pics if you have some. what shape is your old truck in? does it need cab corners, rockers and steps, cab mounts, floor section below the vents, cowl sections, door pillars front and rear, roof eyebrow, etc? mine needed all that and if I was to do it again I may just buy the complete aftermarket cab and save the time.

here is a link to some frame dimensions
http://www.chuckschevytruckpages.com/framespecs.html
I have also heard that the newer trucks like 88-98 have the same frame width. you could try googling
gmupfitters
for info on that.
good luck, take pics, keep us updated, stay warm.
dennis

[55dude]

guys i just got rid of a 59 on a 70 chassis that was that way when i got it and they took the cab mounts off the 59 frame and put them on the 70 chassis, then they used pipe sections standing vertical and bolted cab on.

[Purcell69]

Bitsa, it can be done, as evidenced above ^^^. I agree the ride for a street driven truck is great in the vintage chassis you are looking for. You can keep the stock chassis height and your truck will still look like, a truck. Or, if you are so inclined, go to aftermarket lowering springs for the canyon carver look, without putting your truck in the weeds.

Obviously, a frame of that vintage will need to be serviced if you expect it to ride right, new suspension bushings all around, springs that aren't 40+ years old, fresh brakes and steering components. The plus side is these are not difficult parts to obtain.

The biggest challenge you will face will be the body mounts. You will need to takes LOTS of measurements to get your body properly situated on your new frame, since it is not an aftermarket frame that was built specifically for your body. One piece of advice would be to start with the bed to frame mounts first. Once that height is correct, you can use it as a reference for the cab mount height. I am assuming, of course that the wheel base on the two trucks is the same.

You will need to make your own cab mounts, either with plate steel, tube steel, or by repurposing the mounts from your old frame. Just be sure you have all of your measurements from the old frame before you cut them off. You will need measurements for front to back, axle centerline, chassis centerline, centerline to sides, and vertical positioning of the mounts. The floor of these cabs is not flat and as I recall from my build, there is a 1" difference between the front mounts and the rear, as I found out the hard way in my build.

The next big hurdle will be your brakes. Are you going with a booster and MC under the floor, or are you going with a firewall mount? If you are going under the floor, you will need to fab your own mount, since the after market kits are usually for the stock frame or a specific aftermarket frame maker. There is no ready made kit for what you want to do if you go under the floor, so no stock brake pedal location. There are ready made kits to mount your brakes to the firewall, that will come with a brake pedal setup and are pretty straight forward installation-wise. Assuming you are going with disc front, rear drum, you will need the proportioning valve from your donor chassis, as the 1959 used a single master cylinder with no proportioning valve, being all drums. You will also need to be able to fabricate some brake lines, since there is no kit for the swap you are doing.

The last part will be your steering. You can separate your stock column from the steering box, use an aftermarket column or truck or van column, and an aftermarket steering shaft to connect it all.

It can be done, the way you want it, but it will take some work, accurate measurements, and a bit of fabrication from time to time to do it right and create the truck you want. I should know, I put my 1957 long bed on a 1994 Dodge 4wd chassis.

-Joe

[59chev]

Depending on the look that you are after, I am an advocate of the camaro clip on the original frame. The camaro clip lowers the truck quite a bit ( about 7 inches ). That combined with a flipping the rear on top of the leaf springs or a 4 link in the back makes for a completely different handling truck.

[dsraven]

if you decide to use the different frame approach, do a check on the "new" frame by:
-set the frame on stands and level it up front to rear with the desired rake angle set up. I used some old jack stands with the moveavble part removed-so just the base-and tack welded some big washers and large threaded rod connecting nuts on top of that. then I used some correspondingly sized threaded rod with a 3/8 bolt welded on the top end-that could be bolted to the frame- to go up to the bottom of the frame rails at the all 4 corners. that way I could level and lock down the threaded rod with jam nuts and I knew it wouldn't move. then mark the floor with tape or paint at the base of each jack stand so you know if they have been bumped out of position.
-then, mark the centre line of the frame-front and rear- and run a laser between the two points. check each crossmember from the front to the rear to make sure the laser is finding the centre of each- that way you know if the frame is straight side to side.
-next do a corner to corner measurement to make sure the frame is not a parallelogram.
-do a check from front to rear to be sure it doesn't have a sag on either frame rail.
-now you know it doesn't need to be tweaked (hopefully) and you can carry on with the rebuild-if that is what you plan.
-remember that if the body is going to be dropped lower over the wheels, than it was when sitting on the stock frame, you may need to bring the front axle centreline ahead a bit to compensate for the angular front wheel opening in the fender. if you don't do this the wheel looks like it is pushed back into the fender. I moved mine ahead about an inch.
- there are frame measurement pics on a site called "the old car manuals project". just remember that the 58-59 frames are a bit longer out front than the 55-57 frames. also the rad support brackets are further ahead on the 58-59. I know this because the 57 gmc truck body I have did not fit on the 58 chevy truck frame that I have it sitting on right now. the rad support brackets had to be moved back and the frame would need to be cut off or the bumper would stick out about a couple of inches.

good luck and keep the pics coming with the progress reports.

[dsraven]

orrieg has a link on his page that takes you old car manuals site. you can pic the year specific icon for details on stuff for your year. cab dimensions etc. if you need a frame drawing of the original there is one for a 56 online but it will be a bit short in the rad support area. it should be correct for the cab mount spacing etc because they all use the same cab dimensions.

[59 Bitsa]

Thanks for all the advise guys.
let me give you a little better idea of what i am working with and plan on doing.
first of all i would like to keep the truck a truck, sitting like a truck riding like a truck but a little better than a full leaf spring truck. i want reliable brakes and steering that i can get parts for at any local parts shop.
The truck will be used for truck stuff, hauling my vintage bikes, the odd parts run, hauling my ass to work a couple days a week, and dont forget about the friday night cruze for ice cream with the grandkids.

My current frame has at some point in its life fell victim to a cutting tourch happy farmer and a blind welder. it can be repaired but if i am going to spend that much time to fix a 56 year old frame and then proceed to bring it up to reliable standards i might as well spend the time swapping in a better frame.

I do have access to a very nice 72 C10 that had a fire in the cab but other than that the frame and related parts are almost mint. i helped the guy rebuild it about 4 years ago. I also have a complete 58 3/4 ton frame that i can take measurements from and also use the body mount brackets.

My plans for the truck are to keep it mostly stock looking. i would like to keep the 235 cid with a 5 speed swap. power brakes and electric power steering. Down the road i may do some body mods like power windows with no vent windows but i would like it to be a driver first.

[Purcell69]

Originally Posted by 59 Bitsa

Thanks for all the advise guys.
let me give you a little better idea of what i am working with and plan on doing.
first of all i would like to keep the truck a truck, sitting like a truck riding like a truck but a little better than a full leaf spring truck. i want reliable brakes and steering that i can get parts for at any local parts shop.
The truck will be used for truck stuff, hauling my vintage bikes, the odd parts run, hauling my ass to work a couple days a week, and dont forget about the friday night cruze for ice cream with the grandkids.

My current frame has at some point in its life fell victim to a cutting tourch happy farmer and a blind welder. it can be repaired but if i am going to spend that much time to fix a 56 year old frame and then proceed to bring it up to reliable standards i might as well spend the time swapping in a better frame.

I do have access to a very nice 72 C10 that had a fire in the cab but other than that the frame and related parts are almost mint. i helped the guy rebuild it about 4 years ago. I also have a complete 58 3/4 ton frame that i can take measurements from and also use the body mount brackets.

My plans for the truck are to keep it mostly stock looking. i would like to keep the 235 cid with a 5 speed swap. power brakes and electric power steering. Down the road i may do some body mods like power windows with no vent windows but i would like it to be a driver first.

It sounds like you have a good plan and a good platform. When I did the Dodge frame, I set it level, and then clamped 2" box tube to the top of the frame rails to use for a reference point when it came to locating the height and position of my cab mounts. This worked ok, but some of my mounts needed to be reworked a bit through trial and error.

The '72 will ride a lot nicer than the stock '58 suspension and power steering and better brakes will make it that much more enjoyable. You may want to explore incorporating the later cab bushings in to whatever cab mounts you create. This will go a long way toward isolating out road noise from your cab. The thin rubber wafers used on the '50s trucks did little more than dampen squeaking from two pieces of metal rubbing together. I found a way to reuse the Dodge bushings in mine and am glad I took the time to do it.

Even though the 72 frame is pretty mint, it's not a bad idea to ensure it is square before you get started moving body mounts. A little extra time spent will be worth it in the long run, given the frame has seen 43 years of use. If it is tweaked, a frame shop can get it squared up before you get started and save you from future headaches.

-Joe