spring perch dimensions.

[makovai]

I need to know what the exact measurement of the 72 and below spring perch dimension as well as the 73 and above. For a 14 bolt. From center pin to center pin.

If somebody's has a link to a site that shows real dimensions from the factory i would really appriciate the link.

 

[ryan22re]

1/2t and 3/4t are the same from 73-91.

1t (whatever year they started to 91)and 72 and prior trucks are the same.

Don't have dimensions, but I'm 100 % on this.

 

[b454rat]

1 tons and 72-earlier, 40.5"
1/2 and 3/4 ton 43.5"

 

[4X4HIGH]

1 tons and 72-earlier, 40.5"
1/2 and 3/4 ton 43.5"

Actually it is 1 ton and 72 and earlier are 40.5" and the 73 and later 1/2 and 3/4 ton are 42.5"

 

[blazin_blazer]

uhhh...my 69 k5 has a '75 dana 44 under the front didn't change a thing except brake lines it bolted right in so what gives?

 

[ryan22re]

Rear axles.

Fronts are all the same.

 

[makovai]

Rear axles.

Fronts are all the same.

Exactly, i'm already finished with the front, it bolted right up. But in 73 Chevy widened the rear of the frames and my 78 14 bolt wont mount to my 72 frame without perch movement. I have already cut one side of the perch and shock mount off, but i'm gonna weld the new perch before i cut the other side off.

Another question?????????

I have 8" of suspension lift, should i add the angle when i weld the perch on or should i leave the angle piece under the springs, and weld the new perches on the same angle as stock?

 

[4X4HIGH]

If it were me i would only tack weld the perch in the position you feel is right then install the axle and check for angle, if it needs correcting i would then break the tack welds and readjust then final weld without using shims.

 

[Beast388]

Let me point out that the 1 ton 73-up and the '72 and older distances are close. The '72 and older actually measure 40" center to center.

 

[55Willy]

let me add that the frame is not wider it is all in the brackets to line up to the spring perches. I have a 68 but run a 78 14bolt with my 2nd gen flip with a pickup front hanger to widen the stance.

 

[u2slow]

I believe the 72-older 2wd w/leafs (1/2ton & 127"WB 3/4ton) are wider spaced than the 4x4s.

 

[jdemaris]

Measurements

Actually it is 1 ton and 72 and earlier are 40.5" and the 73 and later 1/2 and 3/4 ton are 42.5"

I measured an 89 GMC 3/4 4WD diesel Suburban last night - since I am stripping it.


Front Springs - 32" width on center, perch to perch 46 3/4"
Rear springs - 42 1/4" width on center, perch to perch 55 3/8"

 

[gmc4cw]

yes, eliminate the shim. remove both old perches. assemble everything loosely without any welds. then you can fine tune the angles and side to side. measure from the backing plates to the perch to center it. then when you have everything where YOU want it, tack weld the perches. unbolt the u-bolts and finish welding.

 

[makovai]

yes, eliminate the shim. remove both old perches. assemble everything loosely without any welds. then you can fine tune the angles and side to side. measure from the backing plates to the perch to center it. then when you have everything where YOU want it, tack weld the perches. unbolt the u-bolts and finish welding.

Hmmm.... i kinda want to do 1 side at a time. but you make a very valid point.

 

[Muddytazz]

Its definitely much easier to do it with the axle temp mounted under the rig to get your angle just right.

 

[makovai]

easier for you guys
I have a 7' door with an 8' truck

I need to find a set of cheap 8 lug wheels for the front.

I am certainly not working on this rig with the 4" of rain per day we have been having. Last winter i did a crate motor in Janurary in the snow. I'm getting to old for this

 

[gmc4cw]

easier for you guys
I have a 7' door with an 8' truck

I have a 7' door and an 8'6" truck.

you only need to put the back end into the door. close enough for the leads on the welder to reach. put the pinion back in or use an angle finder against the mounting surface. If you do it outside the truck and have the perches off even the slightest amount you will need to take it all back apart again.

It really is the best way if you don't have a fancy jig to make sure everything is perfectly straight. jackstands and a concrete floor are not accurate enough for me.

 

[Muddytazz]

Jim, just roll it in on an old set of rims

 

[makovai]

Jim, just roll it in on an old set of rims

thats what im gonna do. I'll start looking on C/l for a cheap set of 8 lug and roll it into the garage for a week or so. I dont want to be rushed.