C20 Moog coil spring replacment options.

[Chilly178]

Hello I'm looking to replace all four coils on my 72 C20. I'm looking at the Moog springs specifically. https://www.moog-suspension-parts.co...20_pickup_1971 I've already decided I wanted to go with a constant rate spring. So that leaves me with two options for the front and back. Standard and HD springs. Moog 6102 vs Moog 6104 for the front and Moog 6101 vs 6103 for the rear. I'm wondering if the HD springs will make the truck sit higher or lower than the standard in the front and back. Which ones should I go with? My truck doesn't have the spid option for the heavy duty springs so i'm thinking I have the regular 3/4 ton springs. Thanks.

[NewBayColony]

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[ThreeQuarter]

My understanding is that any of these springs shouldn’t change the ride height of an empty pickup, only the spring rate. I’ve talked with Gary at Eaton Detroit Spring about differences between C10 & C20 coils (frt & rr) in these years and he says the same.

[Chilly178]

Originally Posted by ThreeQuarter

My understanding is that any of these springs shouldn’t change the ride height of an empty pickup, only the spring rate. I’ve talked with Gary at Eaton Detroit Spring about differences between C10 & C20 coils (frt & rr) in these years and he says the same.

Hmm not according to robnolimit's "make it handle" thread.

Moog # 6082 722 lbs/in 6 cyl, and light v-8
Moog # 6542 842 lbs/in std v-8
Moog # 6102 1015 lbs/in bigblock, longbed c.s.
Moog # 6104 1016 lbs/in 3/4 ton, sits 1/2" higher than #6102
Moog # 6454 1060 lbs/in 3/4t bbc, c.s, 1ton

I'm wondering when he says a 1/2" higher is he talking about ride height or overall height of the spring?

[ThreeQuarter]

Interesting, I didn’t realize Moog had that many options for front springs. Are all of these springs supposed to be spec’ed after a factory spring? Or are some of them unique to Moog?

I think when they refer to the height where it “sits” I think they are comparing installed springs. These springs are various heights when uninstalled, and some of the lighter springs are likely to be taller than the heavier ones.

[rpmerf]

You should be able to calculate how much the spring will be installed given the spring rate, uninstalled height and weight of the truck at the front wheels.

[Chilly178]

Originally Posted by ThreeQuarter

Interesting, I didn’t realize Moog had that many options for front springs. Are all of these springs supposed to be spec’ed after a factory spring? Or are some of them unique to Moog?

I think when they refer to the height where it “sits” I think they are comparing installed springs. These springs are various heights when uninstalled, and some of the lighter springs are likely to be taller than the heavier ones.

I'm thinking they are trying to replace/mimc the original specs. Maybe the HD springs they have are what came in the camper specials and any C20 with heavy duty spring options? If this is true then that would mean the camper specials sit higher than a regular C20?

Edit: I found a post for the rears. http://67-72chevytrucks.com/vboard/s...d.php?t=559203

1/2 ton and std 3/4 ton use the same spring. HD-3/4 did use a heavier spring. I put a set of 1/2-3/4 ton springs into my first 71 C20 Custom Camper and they handled the 11' camper and a loaded boat without any problems. It still had a terrible ride until I put 2000#'s of sand in the back. I can't imagine how the HD springs would have been like.

This is correct. Standard coils on 3/4 ton 2000lb same as heavy duty coils on a 1/2 ton 2000lb. Standard coils on a 1/2 ton is 1250lb while heavy duty coils on a 3/4 ton is 3000lb. This reminds me of a thread about a week ago, comparing coils ride vs leaf, without mentioning the type of coil: standard coils or optional heavy duty coils.

Some good information here. I don't want my truck to ride any higher than it has to with these HD springs, yet I plan on buying a car hauler and I don't want to be over loaded or anything. Hmmm.