55.2-59 Building a Task Force 4x4 with stock frame.......whose done it?

[NW Task Force]

I am planning to convert my 2wd 1957 1/2 ton short box to a 4x4. I'm interested in using 1/2 ton axles (73-80 square body K5/K10).

Besides OrrieG, who has done this conversion using their stock 55-59 frame? I'm looking for chassis details on how the axles are bolted up to the stock leaf springs, transfer case bracing, and steering setups.

[1project2many]

I grew up in a time when this type of conversion was much more popular than a frame swap. Where I lived folks would graft whatever axle to whatever frame and run it 'till it blew up. Some conversions were better, some never made it out of the garage.

The first issue to overcome is going to be the rear crossmember under the bellhousing. If you want to use a married transfer case and transmission combination you will need to install a rear crossmember under the Transmission / transfer case mount. The TF crossmember under the trans will need to be removed or better yet, modified to provide some support without interfering with the trans or bellhousing.

The chassis and engine of the truck are fairly clear so you can run either driver's side or passenger side differential on the front end. Exhaust configuration isn't usually an issue although ram's horn manifolds or center outlet shortie headers generally make the process easier.

Axles tend to get wider as you move up in years. So do the spring widths. The 73+ K chassis trucks moved the leaf springs outboard of the frame. On the axle the LH spring mount is machined into the differential housing. If you choose to use this series axle you will have a large project ahead if you try to keep the TF springs in the stock location. Folks used to cut off the OE springs and move them outboard. The K axle springs are wider than TF springs so you will need sleeves over the U bolts and a custom upper plate if you don't switch to wider springs. The stock springs are positive arch, the K truck springs are reverse arch. The TF axle is a drop axle, the K truck axle is straight. The combination of straight axle and positive arch spring will lift the front of a TF truck over 4". You will need spacers on the rear axle... Big spacers. Front shocks on the K axle attach to the outside of the frame. Frame width doesn't match but shock mounts can be fabricated for the TF frame. The K trucks use a massive front sway bar. It can be used for this swap but one or both ends will end up under a frame rail. I have one on my 2wd truck and sometimes it contacts the frame.

If you use the K series rear axle with TF stock springs you will need to move the spring pads inward. You will also need to find a way to connect park brake cables. That wasn't a detail we worried about "back in the day." Stock short bed driveshafts may work but be prepared to cut n weld or to visit a driveshaft shop.

The stock master can be used for a disc front / drum rear. It doesn't have a large reservoir so checking fluid level over time will be critical. Still, it's better to switch to a two chamber master for this application.

The wheel bolt pattern is the same but offset is different and so is the center diameter of the wheel. So new wheels are in order.

My plan years ago was to get a 67-72 Dodge 4X4, Jeep J10, or an International Travellall front axle. The axles were fairly close in width. The early Dodge, International, and some early Fords used a divorced transfer case which could be attached to the TF transmission. Switch the front end to 3.90 gears and redrill the wheel flange for six lug. The early axles are drum brake so you can keep OE master. They have narrow spring perches and are closer to the TF front axle width.

[mr48chev]

Seriously good info there. As he said, that used to be the way it was done all the time. You stripped a later model wrecked 4x4 of all it's 4x4 pieces and put them on your frame using your springs.

I wouldn't limit my thinking to just GM axles though as there may be a combo that is a better fit width wise than the square body axles.

Sneaking over on the Jeep forum I found a fairly comprehensive list of 4x4 axle widths. They aren't the strongest axles in the world but some of those Cherokee and grand cherokee axles are pretty close to spot on width wise for AD and TF trucks.
https://www.jeepforum.com/forum/f310...idths-3056049/

[NW Task Force]

1project2many,

Thank you for the detailed information! I learned many things reading your post.

I'd like to keep my build all GM and use the stock Task Force leaf springs. With that said, I guess I'll need to relocated the axle spring perches.

Ideally, I am looking for a 73-79 K10 or K5 blazer as a donor rig with the following equipment:
350cid engine
TH350 w/NP203
Dana 44 front
12-bolt rear

I'm hoping I can get in contact with OrrieG to ask some specific questions. I read his build and basically want to do the same thing. I'd like to keep the requirement of welding to a minimum if possible. If I can use existing holes in the frame and bolt components on, that would be great. I realize some level of fabrication will have to be done.

[1project2many]

I'd like to keep my build all GM and use the stock Task Force leaf springs.

Through many of the years GM was building 4X4 trucks, the front axles and transfer cases were not "GM." They were Dana / New Process parts ordered by GM to their specifications. And it is common among auto manufacturers to select parts from a supplier which provides the best answer at the best price. If you consider using an axle, transfer case, or transmission from another supplier then you are doing the same as OE. Simply ensure the parts are manufactured by one of the first tier OE suppliers rather than a "not GM" OE and you're good. 8-)

Some info to help you make decisions:
http://67-72chevytrucks.com/vboard/s...d.php?t=436954

https://67-72chevytrucks.com/vboard/...94&postcount=7
Here Orrie says "no adaptation needed." Not how I remember it but Orrie always did top notch work so I'd consider his answer more accurate.

https://67-72chevytrucks.com/vboard/...highlight=1956

This should be a good start.

[CTOMPKINS]

Not much help right now but im in process on a 59 longbed fleetside now. I got a Dana 44 and 14 bolt.

[NW Task Force]

One of the things that has me a little puzzled is the power steering options for running 4wd on a stock frame. On stock 2wd & 4wd pickups a person can use the 70's/80's style saginaw steering box mounted forward on the frame with spacers and a custom cut plate. No adapter plate to my knowledge is available in the aftermarket world. I guess a company used to have them in their kits, but now just offer bolt spacers. Many factors play into doing a saginaw box...... drag link size, proper sized pitman arm, cutting a notch for a custom steering shaft through the inner fender and tire clearance issues with the box mounted outside of the frame.

Another option I see for 2wd folks is the "bolt-in" CPP power steering box. This unit is supposed to be a toyota box that directly replaces the original OEM manual box on the frame. Pretty slick if you ask me. The biggest question: Can you and has anyone used this CPP power steering box in a 4wd application? If this has been done, boy i'd love to see it.

[farmall]

86-91 Wagoneers came with Dana 44s front as rear. 6 lug, disk brake.

[NW Task Force]

Originally Posted by farmall

86-91 Wagoneers came with Dana 44s front as rear. 6 lug, disk brake.

Farmall, thanks for the info. I imagine these Dana 44's were narrow, making them fit 55-59 trucks very well.

[1-ton of fun]

i have recently decided to go this direction and i am wading through the details now...

i just removed my toyota style steering box as it was interfering with the headers i needed to run for my angle plug heads...but also the pitman arm goes front to back (horizontal shaft) instead of side to side (vertical shaft), which is what is needed for crossover steering, which is the way to go on a lifted 4x4 to avoid bump steer.

right now i'm working on removing my drop leaf springs, which springs to use to clear the tire setup i was looking at (35's), and how to mount them. wanting to ditch the stock brass bushings, and get springs with poly bushings as well. it does appear that 1976 cj5 front leaf springs are similar in dimension, and there are a few lifts spring options available for that application.

[Kula57]

Iv'e been wanting to go 4x4 myself.

one thing to consider in lifting the rear is the shackle flip kit from companies such as ORD. the shackle flip gives you a 4" lift just by using the shale flip. may need to use donor springs from box chevy.

I was also wondering if anyone has used the CPP power box as i already have this set up on my truck.

i'll be keeping an eye on this thread. can't wait to see post and discussion on this topic of 4x4 on stock frame.

aloha