C20 Longhorn front leveling clarification?

[asickber]

I've been researching this and would like some confirmation before I proceed in trying to lift the front to level things out. My Longhorn has a BB and AC and all Longhorns are sitting on one ton frames from my understanding. I've seen where people have used Moog 6454 coils to get the desired results ( http://67-72chevytrucks.com/vboard/s...ight=C20+level). It seems that the Moog 6454 will level out a C20 SBC no AC truck. Would it be enough spring to level out a BB AC Longhorn?

[davischevy]

I don't have the answer to your question, but, my big block Longhorn has the original springs as far as I know, and sits relatively level. I have struggled with the spring question before with other vehicles, and it can be trial and error sometimes. Orielly lists Moog 6104 for C20, big block springs. They don't list the Longhorn specifically. They also don't list a number for a one ton chassis.

Like I said, i don't have an answer.

[Aruba1]

What is the weight difference between a SBC and BBC?

[hamjet]

150 to 200 lbs. depending on aluminum intake or headers..

[asickber]

Nice Longhorn DavisChevy!
So the motor is ~175lbs heavier, plus AC, plus a little weight from a thicker frame. Is this enough to cause a big difference in the stance if I go with the Moog 6454s like I've seen others do with a C20 small block w/o AC?

[Aruba1]

I vote for the Moog 6454 also. Whatever you do, don't go with the 6560 as those have different spring load height and it won't unless you have a backhoe to put some pressure on the front end. After it fits you will be riding down the road as astronauts walk on the moon, lol.

I hope to upload some pics of my C20 with the 6454 sometime this weekend.

[Longhorn 70]

I have the BBC/AC springs on mine. It does sit about an inch lower in the front than the rear. It is kinda hard to tell in the pics. One is sitting on a slanted drive way and the other the tree is blocking the rear.

As I recall, when I went to buy new Moog springs, The choices were

1. Small Block
2. Small block with A/C
3. Big Block

The last 2, Small block w/AC and Big Block were the same part number. I don't know if they have changed since then.

[BET68]

I DON"T THINK ALL LONGHORNS ARE ON A 1 TON FRAME,LET ME KNOW IF I'm WRONG.

[67 cst swb]

Let's see if I can shed some light here.
Moog 6082 Std Duty - Spring rate = 722lbs/inch, Load = 2406lbs, free height 13.18", installed height = 10.00", wire dia .75"
Moog 6104 HD w/ AC - Spring rate = 1016lbs/inch, Load = 2950lbs, free height 12.94", installed height = 10.00", wire dia .82"
Moog 6454 BBC 73-later - Spring rate = 1060lbs/inch, Load = 3841lbs, free height = 13.61" = installed height = 10.00", wire dia .82
In looking thru the Moog online electronic catalog. http://www.fme-cat.com/application.aspx
It appears that Moog lists the same replacement coil spring for all 67-72 10/20/30 series trucks (I did not check every possibility), difference being Standard duty or Heavy duty.
The Moog 6454 is listed for the 73-later BBC applications.

I remember from years ago, the listings were more along the line of engine size and with or without AC. But as you can see from the link above. Things seem to have changed. Bummer!
In my first 67 1/2ton 2wd shortbox (in 1988) I bought BBC spring 6454, then cut a coil out of it to lower it. Then 68-72 El Camino rear variable rate coil spring CC507 to get the back lower but still be able to haul alittle bit.
It drove great in corners.

[Longhorn 70]

There are other springs available. Rancho makes a spring to lift the front end. I had them installed on my truck for about 6 months. They did raise the truck but they also put it against the suspension bumpers. They also made the truck ride like a beach ball. I had 12x15x33's under the truck and it looked good. It didn't handle nor ride comfortably.

[derotoreut]

Originally Posted by 67 cst swb

Let's see if I can shed some light here.
Moog 6082 Std Duty - Spring rate = 722lbs/inch, Load = 2406lbs, free height 13.18", installed height = 10.00", wire dia .75"
Moog 6104 HD w/ AC - Spring rate = 1016lbs/inch, Load = 2950lbs, free height 12.94", installed height = 10.00", wire dia .82"
Moog 6454 BBC 73-later - Spring rate = 1060lbs/inch, Load = 3841lbs, free height = 13.61" = installed height = 10.00", wire dia .82
In looking thru the Moog online electronic catalog. http://www.fme-cat.com/application.aspx
It appears that Moog lists the same replacement coil spring for all 67-72 10/20/30 series trucks (I did not check every possibility), difference being Standard duty or Heavy duty.
The Moog 6454 is listed for the 73-later BBC applications.

I remember from years ago, the listings were more along the line of engine size and with or without AC. But as you can see from the link above. Things seem to have changed. Bummer!
In my first 67 1/2ton 2wd shortbox (in 1988) I bought BBC spring 6454, then cut a coil out of it to lower it. Then 68-72 El Camino rear variable rate coil spring CC507 to get the back lower but still be able to haul alittle bit.
It drove great in corners.

I used NAPA springs same as the Moog 6454 installed on my '69 C20 (its for sale now) http://67-72chevytrucks.com/vboard/c...m-build&cat=12.

When I did front disc conversion I changed out the front springs. I installed some HD springs (P/N 2772074) bought from NAPA. The stock HD C20 springs are as follows:

http://www.napaonline.com/Catalog/Ca...752_0162319756

Part No.: 2771752
No. of Coils: 7.92
Free Height: 12.94"
Spring ID: 3.68"
Spring Load Height: 10"
Design Load: 2950
Spring Rate: 1016
Wire Diameter: 0.812"

The springs I put on from C10, C20, C30 from 1973-83. They are as follows:

http://www.napaonline.com/Catalog/Ca...074_0162301536

Part No.: 2772074
No. of Coils: 8
Free Height: 13.61"
Spring ID: 3.676"
Spring Load Height: 10"
Design Load: 3841
Spring Rate: 1060
Wire Diameter: 0.83"

You could also use C30 mid '80's 1-ton springs, but I thought they would be too stiff. Those are:

http://www.napaonline.com/Catalog/Ca...085_0162304063

Part No.: 2773085
No. of Coils: 7.93
Free Height: 13.34"
Spring ID: 3.65"
Spring Load Height: 11"
Design Load: 3289
Spring Rate: 1318
Wire Diameter: 0.906"

The wheels are chrome Hummer H2 wheels from 2003-07.

[SS Tim]

Originally Posted by BET68

I DON"T THINK ALL LONGHORNS ARE ON A 1 TON FRAME,LET ME KNOW IF I'm WRONG.

All Longhorns from 68-72 have the same frame. 133" wb, 7.20" section height, 2.77" flange width, 0.194" thick, 5.05 section modulus.

But they do have different 3/4 or 1 ton suspension spring rates and axles as base equipment.

[Aruba1]

DO NOT use any springs that are over the stock height of 10". If you go higher you will need to use something like a backhoe to compress the front end because the weight of the truck will not be sufficient to compress that extra height. Yes, BTDT with a John Deere 310B on the following spring...

"You could also use C30 mid '80's 1-ton springs, but I thought they would be too stiff. Those are:

http://www.napaonline.com/Catalog/Ca...085_0162304063

Part No.: 2773085
No. of Coils: 7.93
Free Height: 13.34"
Spring ID: 3.65"
Spring Load Height: 11"
Design Load: 3289
Spring Rate: 1318
Wire Diameter: 0.906""

But if you want to take a chance, lol, I still have a brand new set in the garage collecting dust. The only got about 1/2 mile on them.

[asickber]

Thanks for all the info. I'm still thinking my best bet is to go with the moog 6454. I'd like to even out the spaces in the wheel wells and give it more of a 4x4 look. Here's what I'm working with.