67-72 Trailing arm suspension in 1957 Truck

[ambryatim]

Hello all, Ok I have searched and came up with a few results, but none that would answer my question.
Has anyone installed the rear suspension from a 67-72 onto there truck???
I was wondering about this, seeing how it has a lot more potential than the ol' leaf springs and will be cheaper to do than a four-link "if" I can find a donor vehicle. I am sure I would have to trim down the crossmember to fit in between my frame rails, but I am thinking very hard about doing this. So, any info or input would be great.

[dwcsr]

If your going to that large a conversion why not just do a 72 frame swap and get the disc brakes and IFS along with the truck arms. Its a great ride on truck arms but not much on load handling.

[ambryatim]

I already have my frame clipped with a subframe out of a 78 Trans AM. If I was just starting out I might do that, but then I would have to relocate the cab mounts etc...With this I should "in theroy" be able to drill holes and bolt it to my existing frame with some reinforcements of course.

Originally Posted by dwcsr

If your going to that large a conversion why not just do a 72 frame swap and get the disc brakes and IFS along with the truck arms. Its a great ride on truck arms but not much on load handling.

[Junkbike]

is this what your talking about? it is going in a 47-53 frame

[ambryatim]

Yes, it is!!! Have you measured to see how much of the crossmember will need to be removed?? I know it will be diffrent for my application, but this is what I am talking about. Are you going to weld the seams on the arms up to make them more ridige???

Originally Posted by Junkbike

is this what your talking about? it is going in a 47-53 frame

[Junkbike]

Its not mine, he has the build thread here.
http://www.jalopyjournal.com/forum/g...ussionid=10029

[LEEVON]

Here's the other build thread from this site, same stuff maybe some better pics here.
http://67-72chevytrucks.com/vboard/s...=383265&page=4

It couldn't have been any easier really, basically I just chopped off the ends of the crossmember and welded to some channels that fit in the frame. I just clamped it to the frame where I wanted my wheel c/l and scibed top and bottom, then cut and weld to the channel. You could also box the inside of the frame and weld to that. My frame rails are tapered, yours are straight making even easier. Are you planning on using stock springs or bags? If you can get the rear shock mounts those can be used too. I can take some measurements if you need, I also have a '71 swb for reference.

[ambryatim]

Just noticed that you installed your own exhaust "tunnels" or cut-outs. LOL!! Shows how observant I am. Nice work, I will have to do that mod too.

Originally Posted by LEEVON

Here's the other build thread from this site, same stuff maybe some better pics here.
http://67-72chevytrucks.com/vboard/s...=383265&page=4

It couldn't have been any easier really, basically I just chopped off the ends of the crossmember and welded to some channels that fit in the frame. I just clamped it to the frame where I wanted my wheel c/l and scibed top and bottom, then cut and weld to the channel. You could also box the inside of the frame and weld to that. My frame rails are tapered, yours are straight making even easier. Are you planning on using stock springs or bags? If you can get the rear shock mounts those can be used too. I can take some measurements if you need, I also have a '71 swb for reference.

[Junkbike]

Hey! there is Leevon now))

[ambryatim]

LEEVON,
Thanks for the info. I plan on using the stock springs for now. Bags are somewhere in the future. Question....what are the little angeled pieces for?? I am not sure what they would be called, but are they a brace or something??

[LEEVON]

If you're talking about the rusty pieces I placed where the springs/bags would go those are just the bed brackets I took off the old frame and set there to see if they would be a good mount for the bags.

[ambryatim]

Mmmm, no I dont think so, they are in the picture (last pic) with all the suspension parts. They are the only parts that are angled/curved.

[LEEVON]

Originally Posted by ambryatim

Mmmm, no I dont think so, they are in the picture (last pic) with all the suspension parts. They are the only parts that are angled/curved.

Oooh, those are the shock mounts they fit under the rear trailing arm. They look different than the ones on my '71 but serve the same purpose. I discovered that you can also swap sides and use them forward or aft.

If you want to keep it real simple have Nathan Porter (porterbuilt) make a crossmember for you and bolt everything up. I was going this route but cheaped out and made my own.

[ambryatim]

Ok, thanks for the cross member info. I might cheap out too...but, I will give it a look.
Where are you going to mount your Pan Hard Bar?? Foward or aft of the Diff??

[LEEVON]

aft, there's not enough room forward. I thought about it though. I might run the shock outside the frame rails (big maybe).

[ambryatim]

LEEVON....
Can you do me a favor??? No rush, but could you measure the width of your frame on the 71'SWB. Just wanting to get an idea of how much might need to be removed from the crossmember, if I decide to go that route. Thanks

[ambryatim]

Does anyone know if the length of the trailing arms are the same for the SWB and LWB trucks???

[chevy_mike]

Originally Posted by ambryatim

Does anyone know if the length of the trailing arms are the same for the SWB and LWB trucks???

Yes, same arms. Crossmember is just located differently.

[LEEVON]

Sorry it took me so long, the stock crossmember on my '71 is 33.5".

[ambryatim]

Ok, thanks. I just found a donor, hoping the guy will let me come pull everything I need this weekend. Oh, I also just remembered that the beds on a 55-66 were all interchangeable. Soooooo....the crossmember should go between the frame rails with no modification, key word "should"...seeing how they are both the same ladder frame design. We will see.

Originally Posted by LEEVON

Sorry it took me so long, the stock crossmember on my '71 is 33.5".

[LEEVON]

One caveat, the frame rails on my truck aren't as deep as the later rails. I had to taper the bottom of the crossmember up about 1/2". Look at the pic where you see the channel on the end and you can sort of see the bottom angled up. I can measure the depth of the '71 frame rails too if you need.

Good luck on the donor stuff, I got mine off Craigslist, had a ton of calls after posting a WTB ad. I really hope this works out for you, trailing arms are great suspensions.

[ambryatim]

Thanks Leevon.

If you would measure the height of the frame itself that would be AWESOME!!! If I remember correctly it is around 6"-7" high. "I think" If so, then it should just slide in between them.

I found this one on Craigs List too. But, its still on the truck. It is a 66 long bed. Never thought about putting a want ad out. I will have to do that if this deal falls thru. I will have to post some pics when I start the install. I am looking foward to the ride.

[LEEVON]

The '71 frame rails are 6" deep (inside-to-inside).

[ambryatim]

Thanks....Now I am just waiting on a phone call to see if he is going to sell just the suspension out from under the ol' truck.

Have a good 4th!!!

Originally Posted by LEEVON

The '71 frame rails are 6" deep (inside-to-inside).

[ambryatim]

Leevon....is there a possibility of you being able to find out at what angle the mounts on the crossmember are at??? And how far apart they are?? I am thinking of just building my own crossmember and building my own arms from this write up.

http://67-72chevytrucks.com/vboard/s...d.php?t=321100