Swap 70 PU Cab to a 1990 Sub 4x4

[WestCoaster]

Hello

I have access to a 1970 PU Cab and Frontend. There is no frame or bed, however I have gone through all the points that harbor rust in this vintage truck and there is none. The farmer has it stored in a hay barn, several in fact.

I have a 1990 4x4 Suburban, solid front axle with a wheelbase of 127, that is a great daily driver that I am considering making into a donor chassis for the 1970 PU.

Is this possible? What are the biggest issues that I will face? Has anyone done this?

Thanks for the time.

[Grim Reaper]

Wheel base is not going to match any bed is the first problem. The wheel base is between a Short beedn and long bed. If you build ad flat bed then no big deal otherwise your going to have to do some serious mods on the bed.

Cab......Nothing is going to line up and your going to have to fabricate it all. It will probably have to sit up like its on a body lift to make it work. If you uses a 73 up cab then all you would have to modify is the Rear Cab mounts. THis is done with K5 frames from time ot time.

[red450ih]

The Suburban frame will work! This is what I wrote a few weeks ago to someone wanting to convert his 63-66 into a 4WD.

Good luck,
Keith


From what I have found the 73-87 Truck frame would not be my first choice of frame for this conversion. This is because the 73-87's have a 45 degree bend right under the cab where the 63-66 do not have this bend, this makes the 73-87 frame difficult to work with. If your 63-66 truck is a short bed, you would still need to shorten a 73-87 short bed frame to match the 60-66 wheel base. The Blazer frame may work better, but I know they are shorter than a short bed truck of the same year.

If your truck is a 63-66 I would suggest one of two frames for the conversion.
1. Find a 67-72 Chev/GMC frame. (long/short bed your choice)
2. Find a 73-91 Suburban frame (If you have a long bed)
The 67-72 trucks have very similar frames to the 63-66 trucks, almost a bolt in job! They share the same cab/bed mounting locations and share the exact same wheel base wheather it be a short or long bed. (Long bed wheel base 127")

The Suburban frames are very similar to the 63-72 long bed frames. Should you use a Suburban frame you will need to remove the cab/mounts from your frame and bolt them to the Suburban 4WD frame. You will also need to move the rear axel spring hangers forward 2.5 inches, this will achieve the correct wheel base for the 63-72 long bed truck. (Suburban wheel base is 129.5")

Q&A:

What truck do you have? I have a 1965 C10 long bed.

Which route did you take? I was looking for a 4WD 67-72 frame or rusty donor truck until I found a rusty 3/4 ton 4WD 87 Suburban for sale locally.

Why the 87 Suburban? All 87 Suburbans had TBI fuel injection, it was 3/4 ton, has front disc brakes, automatic trans, 14 bolt rear axle. The Fuel injection really caught my eye.

Have you done the swap? No, I haven't done the swap yet mainly because it's too cold for me to work in the shop (poor heater). Should be done by mid summer.


Here are the wheel bases:
73-87 Short 117.5"
73-87 long 131.5"
73-91 Sub 129.5"
73-91 Blaz 106.5"
60-72 Short 115"
60-72 long 127"

Hope this helps.

Keith

[Grim Reaper]

Good post Keith.

After seeing the wheel bases it may not be as bad as I thought. You could more the spring purches forwad 2.5 inches in the rear without much problem and get the wheel base to match the 67-72 wheel base. If there is enough tail on the long bed then it will cover the frame. Still have ot do all custom mounts.

Fact of the matter is frames show up all the time. You could find the right frame and swap your drivetrain onto it with a lot less hassle. There is proababy 2-3 frames available right now in the 67-72 for sale section.

[Grim Reaper]

If your willing to make a little trip here is EXACTLY what you need.
http://67-72chevytrucks.com/vboard/s...threadid=90150
That's a rolling 71 4x4 lwb frame WITH a bed and axles in TX. Need,s cab and clip and he has some clip parts as well. If the 90 you have is 1/2 ton this probably has a better rear axle with a 12 bolt BUT the front axle is a D44 with small u-joints. You front axle is stronger.