Were Trailing Arms an Option?

[jim-bob]

..got a 67 GMC Short Stepper (No Eng.or Trans yet)
There are no Trailing Arms and no mounting brkts on the axle nor the cross member..it has the leaf springs now..I thought all the 67-72 were factory installed but I don't know whole lot..So are they a factory option or dealer installed?
Anyway I do want them installed after the frame is blasted and painted..(I'm just assuming that I want them based on some post I've read..Is there something better?
I would appreciate some advise/ suggestions on which way to go in buying them and brackets..Should I look for used ones or new ones..Is there a template for welding on the brackets? IF i lower the trk at all it will only be 2/4..Your help will be very much appreciated.

[Boog]

On 67-72 Leaf springs were standard on GMCs and coils were standard on chevys. You can swap them if you like.

[Bigdav160]

Aren't the frame rails different? With the trailing arms you have that large crossmember in the middle of the frame.

[69gmcc10]

No difference in the frames and the crossmember the arms mounts too is on all trucks unless removed by someone after the fact. I did a trailing arm conversion on my 69 GMC, it is documented in my sig.

[michael bustamante]

that trailingarm cross member will be easy to find but a pain in the butt to remove.

[jim-bob]

..the cross-member is on there now where the drive shaft came thru but I would like to have the new style with holes for twin exhaust.. also i believe the arm brackets are welded on this piece but is there a diagram showing where to weld the arms on the axle?

[Boog]

You do not weld the trailing arms to the rear end. They are u bolted to it like leaf springs only the axle pads are at an angle on the coil spring setup.
Unless you are talking about a 4 link setup? Whole different deal there.

[PGSigns]

Find a donor for the parts you need and get a coil rear housing. Lot less work and the housing will be nice and straight if you don't weld on it.
Jimmy

[jim-bob]

..nope Boog, not thinking bout a 4-link system..Seen one on line but don't know if I should even think that route..So I remove the leaf springs and used those u-bolts to attache the arms to the axle..Does anyone know of any assembly pics or videos?

,,ADD ON (Just read this on line)...."If you are going to reuse the axle assembly, you will need to remove
the spring perches and shock mounts from the axle tubes. You will
need to clean or strip the axle tubes to bare steel. New brackets will be
welded to the axle tubes later" (would u know if this pertains to my 67 GMC?

[jim-bob]

Originally Posted by PGSigns

Find a donor for the parts you need and get a coil rear housing. Lot less work and the housing will be nice and straight if you don't weld on it.
Jimmy

"coil rear housing" that throwed me off..sorry to ask but what is it?

[oldman3]

Here's three pics showing a coil spring rear axle. The pads are welded in an angle, not straight like leaf springs. The last pic shows the trailing arms installed, with springs etc. Here you can see how the arms are on an angle going toward the center mount. Hope these help...Jim

[jim-bob]

Originally Posted by oldman3

Here's three pics showing a coil spring rear axle. The pads are welded in an angle, not straight like leaf springs. The last pic shows the trailing arms installed, with springs etc. Here you can see how the arms are on an angle going toward the center mount. Hope these help...Jim

Yes they really help..pics are worth a k words..Thanks oldman3

[jim-bob]

..your right Jimmy (PG Signs)...I need me a Donor!! Thanks

[69gmcc10]

Here are some pics form my conversion. You can read about it in more detail in my build thread below. I flipped the trailing arm mounts for more traction, 2" lowering blocks to lower the truck and keep the ride as stock as possible, and a No Limit panhard bar for smoother deflection in suspension travel.

[69gmcc10]

I sourced the trailing arms spring and shock mounts form 1 truck and the crossmember from another, as stated before the crossmember doesn't exactly fall out!

[jim-bob]

Originally Posted by 69gmcc10

I sourced the trailing arms spring and shock mounts form 1 truck and the crossmember from another, as stated before the crossmember doesn't exactly fall out!

Great shots 69, thanks..So you didn't have that cross member on your truck so you cut it off a donor and welded it on your frame?..It looks just like my original except for the exhaust pipe holes..Did you make those or were they already cut in?
I can't see in the pics how you mounted the arms to that xmember..did you buy prefab brkts and weld them on or what?

Thanks again 69, 'preciate the schematics..

[PGSigns]

If you find a donor you can get all the brackets and cross members you need. An option on the front trailing arm cross member is an after market one and it will have the brackets and the holes you want. You will also need the rear shock cross member. as it also supports the coil springs. For a track bar an aftermarket one from porter built or no limit will include the frame bracket you will need. If going stock on that one you will need the bracket from the donor. His exhaust holes were added to the stock crosmember and welded in.
Jimmy

[69gmcc10]

The crossmember that the arms mounts to is on ALL 67 to 72 trucks, it is riveted from the factory to the frame rails and is bolted in through the factory holes on the aftermarket members, the factory members even have the rivet/bolt holes to mount the trailing arm brackets to. The exhaust holes need to be cut with a hole saw and reinforced with the pipe. I recommend a 4" OD pipe or larger, anything smaller doesn't have much room around a exhaust. My trailing arm brackets came from the donor truck I got the arms from and have 2 extra holes in them because I flipped them upside down when I bolted them on the crossmember where the factory rivets would be (you cant see the mounting holes on the crossmember in the photo because I painted them black after I drilled new holes to prevent rust on the new holes, but they are between the carrier bearing and the cutouts for the exhaust routing).

In all, as PGSigns said it would be easiest to just find a donor truck for all of the parts. Total pars needed starting from the front to the back are; the crossmember to trilig arm mounts and bolts to mount them, trailing arms (you may as well replace the bushings while you are at it), The upper spring and shock mount crossmember and bolts to mount it(the one crossmsmber you are missing), Shocks and mounting bolts, coil springs and mounting bracketry for them (2 bolts and retainers), U bolts 1 for each side (3/4" rod, 3 1/2" gap, length determined by if you run lowering blocks or not), lower shock mounts that mount to the bottom of the trailing arms by way of u bolts, axle saddles from ECE to weld to your axles, you may want to look into a longer brake hose (just in case), and a panhard bar with mounts and hardware (go aftermarket and get a long one).