Daughters ‘87 needs to ride smooth.

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,955
Reaction score
12,193
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
I didnt realize all the info needed for the questions. You’re right they’re 31x10.50x15. It’s a 350sbc. I’m going to drop the pressure on the tires (pressure was filled to max psi)and see how that may help, thanks.
That will be huge.
 

Redfish

Full Access Member
Joined
Nov 6, 2021
Posts
2,632
Reaction score
14,203
Location
Prairieville, LA
First Name
Andrew
Truck Year
1987
Truck Model
V1500
Engine Size
350/5.7
My memory of those trucks seems to be different from most of you. The 2wd square bodies were usually pretty smooth riding. I cannot remember how many times in the '80s I heard someone say, "This truck rides like a car!" Of course the top of the line trucks came with white wall "car" tires.

It looks to me as though your tire choice is not helping you. They may look cool but if they are aired up to max pressure, they are going to be stiff. @Grit dog and I are in agreement on this.

I would try replacing the front coils with a new set as close as I could get to the OE spec. The leaf pack in the rear rode pretty smooth in its day. You can affect the ride quality front and rear with the right shocks also. When that truck was new a set of Monroe Gas Magnum shocks would really make the ride stiff but they helped it handle better on a curvy road. The factory shocks were usually shot after 30K miles or less.
 

legopnuematic

Licensed Junk Dealer
Supporting Member
Joined
Oct 27, 2016
Posts
2,466
Reaction score
6,298
Location
MO
First Name
Spencer
Truck Year
1971, 1̶9̶7̶4, 1976, 1979,1̶9̶8̶5, 2002
Truck Model
Dart Swinger, Sierra 10, C10 Cheyenne, C10 Big Ten, Silverado 10, Ram 2500
Engine Size
225/6, 350 c.i., 350 c.i., 5.9l Cummins
My big ten has lots-o-leafs too, the original owners even added a 3 or 4 leaf overload pack on top.

You must be registered for see images attach


I’ve got 31x10.50x15’s (BFG K02s) on a 15x8 wheel on my 76 c10, I’ve put 30-40k miles on them and I don’t think it rides bad at all. That is even taking trips up to northern IL and southern Wisconsin with their barely existing roads (looking at you Winnebago County) and vehicle swallowing potholes (Milwaukee).

Maybe I just have low standards or expectations.
 

gogo14910

Member
Joined
Dec 19, 2021
Posts
45
Reaction score
74
Location
Texas
First Name
Joe
Truck Year
1987
Truck Model
R10
Engine Size
350 SBC
My big ten has lots-o-leafs too, the original owners even added a 3 or 4 leaf overload pack on top.

You must be registered for see images attach


I’ve got 31x10.50x15’s (BFG K02s) on a 15x8 wheel on my 76 c10, I’ve put 30-40k miles on them and I don’t think it rides bad at all. That is even taking trips up to northern IL and southern Wisconsin with their barely existing roads (looking at you Winnebago County) and vehicle swallowing potholes (Milwaukee).

Maybe I just have low standards or expectations.
Is it softer ride to have more or less leafs?
 

legopnuematic

Licensed Junk Dealer
Supporting Member
Joined
Oct 27, 2016
Posts
2,466
Reaction score
6,298
Location
MO
First Name
Spencer
Truck Year
1971, 1̶9̶7̶4, 1976, 1979,1̶9̶8̶5, 2002
Truck Model
Dart Swinger, Sierra 10, C10 Cheyenne, C10 Big Ten, Silverado 10, Ram 2500
Engine Size
225/6, 350 c.i., 350 c.i., 5.9l Cummins
Yes and no. It depends on quite a few factors.

The thickness of each leaf, the width, the overall length, shackle configuration.

If you look at a trailer spring, they are fairly short, narrow, thick leafs with just a few of them in a pack, they are rated for pretty high loads.

Or a (say for example 2nd gen dodge truck) “newer” 3/4 ton, my Cummins has 3 or 4 leafs in the pack, but they are 3” wide and thick leafs, aftermarket springs sold by Carli have at at least 10 leafs, but are thinner, and are rated lower than what the factory setup are (for payload), but should ride smoother and promote more flex and travel than OE.

So it really depends.
 

Hunter79764

Full Access Member
Joined
Sep 1, 2021
Posts
343
Reaction score
527
Location
Grand Prairie, TX
First Name
Shawn
Truck Year
1987
Truck Model
Suburban V20
Engine Size
350
Start with 25 psi all around and see what that does, I bet you'll be amazed. Then dig in on bushings and springs, or maybe go shocks first. No experience on brands for smooth ride, but if you REALLY want the 77 Caddy ride, I'm sure someone has a set of blown out stock shocks they could send :) Otherwise I think cheaper shocks would be smoother after a break in period, but something like Bilstein is going to be objectively "better" but not necessarily float down a lazy river smooth.
 

squaredeal91

Full Access Member
Joined
Mar 10, 2023
Posts
2,509
Reaction score
4,514
Location
Cave junction Oregon
First Name
Greg bush
Truck Year
1991 SB
Truck Model
K30
Engine Size
5.9 Cummins 12 valve
These squares IMHO ride better than new cars. New cars/trucks ride smoothly but still feel like a brick. Not a popular opinion but that's how i feel. My k10 shorty has an all wood bed on it and is too light kinda hurts my back on bumpy roads. (Putting original bed on soon) rides much better with weight in the back. I'm constantly leaving things in it for a better ride. It has the quad shocks on it all around. I know I can improve my ride by removing half of them I bet. Even heard guys sometimes drill holes in half of them to make them dummies. My sons 85 2wd fleet long rides really nicely the way it is.
Springs play allot here and so do tires as well pointed out.
All this to say lol. Monroe makes a self adjusting gas shock that stiffness on windy roads and softens back up when on flats or whatever. I haven't personally used them but have always planned getting them for my car. The guy who told me about them really liked them.
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,693
Reaction score
6,867
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
Sorry R10, 2wd
replace all bushings

Anything sprung weight that can be reduced will help, but theres only so much you should lighten on the front end, and thats Maybe? with aftermarket arms? I could be wrong, but i dont imagine that would save much weight

The proper shock, and as said, the rear spring situation

But if you can isolate the cab from the frame with a custom or aftermarket cab mount, that might help. Nowadays instead of engineering trucks and frames they just engineer NVH isolation methods for the cab, gmt900 trucks are notable for this because its functionally a gmt800 frame and all that, but the cab mounts are entirely different.

Late late gmt800 got some of the engineering changes as running changes , TSBs on them make it look complicated as hell and frankly dumb, in my opinion, but if you wanted to reverse engineer modern truck cab mounts to your square that would probably make it ride a lot nicer. Then a new rag joint for the steering wheel, little rubber bits for the rear leaf springs that limit the slap and vibrational transfer from the axle

having good engine/trans mounts

Dont do poly.

THen good PT tires

But at that point you have spent so much time trying to make the truck not a 1987 Chevy, why not just get a 2wd gmt400 from the mid 90s? Would be smoother and has more interior love that also isolates (remember, insulation, trim, rubber seals.. all play a part.. you could do this to your square too.. but its time and money. )
 

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,955
Reaction score
12,193
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
My big ten has lots-o-leafs too, the original owners even added a 3 or 4 leaf overload pack on top.

You must be registered for see images attach


I’ve got 31x10.50x15’s (BFG K02s) on a 15x8 wheel on my 76 c10, I’ve put 30-40k miles on them and I don’t think it rides bad at all. That is even taking trips up to northern IL and southern Wisconsin with their barely existing roads (looking at you Winnebago County) and vehicle swallowing potholes (Milwaukee).

Maybe I just have low standards or expectations.
WOW! That’s way more spring than axle!
You have basically the same truck and tires as the OP. Maybe share your tire pressures when running around bobtail.
 

legopnuematic

Licensed Junk Dealer
Supporting Member
Joined
Oct 27, 2016
Posts
2,466
Reaction score
6,298
Location
MO
First Name
Spencer
Truck Year
1971, 1̶9̶7̶4, 1976, 1979,1̶9̶8̶5, 2002
Truck Model
Dart Swinger, Sierra 10, C10 Cheyenne, C10 Big Ten, Silverado 10, Ram 2500
Engine Size
225/6, 350 c.i., 350 c.i., 5.9l Cummins
WOW! That’s way more spring than axle!
You have basically the same truck and tires as the OP. Maybe share your tire pressures when running around bobtail.
So the photo above is of my 79, that has not been driven yet. So I cannot speak to how it rides. But the springs are "Blueprinted" from what originals were, 79 Big 10, 6200lb GVWR, 56" springs. Had them made at a local spring shop, they pulled the information from their vintage books.

But if I step in the bed I can flex them, or wiggle the truck. So I don't believe it is going to be a total log wagon.

Here is a photo of the original 79 springs with overloads, there is/was wear on the rubber bumpers that I believe it was loaded enough to use the overloads on multiple occasions.
You must be registered for see images attach


Now my 76 is a non F44 (non big ten truck), 5400lb GVWR, 52" springs. Best photo I could find that you can see the springs. 6 leafs I think?
You must be registered for see images attach


But I have put about 60k miles on the 76, I've always thought it rode fine, never any complaints from others. There has been a 30 gallon engine drive compressor living in the bed for 4 or 5 years now, so that certainly would help. Even before the compressor I never thought of it as a log wagon.

I don't remember what I have for tire pressures, but it's probably 35-40psi all around on the 31s.

With the 235/75/15s before it was what the door chart says, 28 maybe?

Maybe I just have low expectations or high tolerance to ride quality... I think it (and the Cummins, and dart) rides better than a lot of new cars do, if says something.
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
10,041
Reaction score
10,132
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
It’s not a rotisserie restoration. I’ll put money in but, she wants the “old” truck. I just want her to have a smoother ride. i.e. dont spill coffee on the interior we just redid. Too bumpy for that right now even on a concrete hwy.
Youre screwed, dude.
Best to buy coffee-colored carpet LMAO!
OMG HAHA that's really funny...

I thought the shocks I bought were pretty great. KYBs.

:signs8::happy175::idiot:
 

Bloodhound1981

Full Access Member
Joined
Nov 15, 2016
Posts
202
Reaction score
454
Location
MA
First Name
Rusty
Truck Year
1981
Truck Model
C-10
Engine Size
5.7
I didnt realize all the info needed for the questions. You’re right they’re 31x10.50x15. It’s a 350sbc. I’m going to drop the pressure on the tires (pressure was filled to max psi)and see how that may help, thanks.
I am running 31x10.5x15 Michelin LTX Defenders, I went from 40psi to 32 and I couldn't believe the difference in ride quality, as far as being less harsh.
 

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,955
Reaction score
12,193
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
I am running 31x10.5x15 Michelin LTX Defenders, I went from 40psi to 32 and I couldn't believe the difference in ride quality, as far as being less harsh.
^Yup.
The tire pressure concept is lost on so many… even “car guys”. It’s sort of mind boggling.
I guess it’s the if “some” is good, “more” is better, so “max” (psi) just has to be bestest!
Worst part is the effin NHtSA is worse than your shade tree, dont know it all, person. They’ve mandated warnings if you don’t run way too much air pressure in some vehicles. IE newer 3/4ton trucks.
Although it is comical to see people who will beat the hell out of their spleens driving around an empty 3/4ton with 100-200% greater pressure in their tires than needed, “or the low tire light comes on.”
 

Forum statistics

Threads
44,101
Posts
949,375
Members
36,198
Latest member
squarebody2013
Top