I'm sure it's an age old question, K 20 ride quality improvements.

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.

midwest

Full Access Member
Joined
Dec 28, 2021
Posts
185
Reaction score
200
Location
Indiana
First Name
Scott
Truck Year
1986
Truck Model
K20
Engine Size
350
My truck started as a 77 K 20 (donor body is an 86). When I drug the truck home 15 years ago it was a mess. Had spent it's life as a logging truck for a timber guy. Anyway I remember pulling the shocks off and they would just slide in and out if I turned them upside down. I remember thinking that explained the rough ride but when I put the new shocks on it wasn't much better. Back then I also replaced the leaf springs. I don't remember what brand shocks I put on it back then but I got them at Napa and they were just a standard OEM replacement shock. I haven't ridden in many older 3/4 ton trucks but I have been told they all bounce around quite a bit. I didn't know if any of the better brand shocks would make much difference or if the truck is what it is. I don't drive it a ton so it's not a huge deal, just thinking of smoothing it out some.
 

Copymutt

Full Access Member
Joined
Jan 17, 2020
Posts
222
Reaction score
674
Location
Colorado
First Name
Jim
Truck Year
74
Truck Model
K20
Engine Size
350
Ha, u should ride in mine w/ overloads. Put a ton or so in the bed. It’ll ride like a caddy.
You must be registered for see images attach
 

GTX63

Full Access Member
Joined
Nov 27, 2022
Posts
934
Reaction score
3,792
Location
Tennessee
First Name
Ty
Truck Year
1985
Truck Model
K10
Engine Size
350
A 77 K20 is going to ride just like it started life as, a log truck. They just do. They are the unfiltered cigarette of trucks. It was a different time then and trucks were made to work in first. Comfort was an afterthought.
The Squarebody frame to chassis is a rigid design. Shocks designed for comfort rather than load, weaker sidewall tires, a fatter seat all put together would make a very slight improvement, but then you lose some of the truck's strength.
There is some truth that a loaded 3/4 ton will ride better than empty.
 

75gmck25

Full Access Member
Joined
Oct 13, 2016
Posts
2,274
Reaction score
2,218
Location
Northern Virginia
First Name
Bruce
Truck Year
1975
Truck Model
K25 Camper Special TH350 NP203
Engine Size
5.7
My K25 is 8600 lb GVW, and it definitely rides better with about 1000lbs in the bed. In that era GM did not use any type of factory progressive overloads, so the full GVW load capacity is there all the time. It’s great for hauling loads.
 

midwest

Full Access Member
Joined
Dec 28, 2021
Posts
185
Reaction score
200
Location
Indiana
First Name
Scott
Truck Year
1986
Truck Model
K20
Engine Size
350
Yeah, it is definitely noticeable how much better it rides with a load in the bed.
 

squaredeal91

Full Access Member
Joined
Mar 10, 2023
Posts
2,540
Reaction score
4,589
Location
Cave junction Oregon
First Name
Greg bush
Truck Year
1991 SB
Truck Model
K30
Engine Size
5.9 Cummins 12 valve
I prefer the way our older trucks drive and feel. To me nothing can compare to a chevy truck. My shortbed k10 needs constant weight in the back for comfort and traction because someone before me put a super light all wood flatbed on it. I have plans to put original stepper on it with paint. Sorry for rambling, But I think the key is less spring pack if you can afford it or keep weight in the bed for comfort.
 

midwest

Full Access Member
Joined
Dec 28, 2021
Posts
185
Reaction score
200
Location
Indiana
First Name
Scott
Truck Year
1986
Truck Model
K20
Engine Size
350
I've rode in plenty of K 10's (and my K 20 for the last 15 years). An old K 10 rides closer to a new truck that it does a K 20.
 

Bextreme04

Full Access Member
Joined
May 13, 2019
Posts
4,440
Reaction score
5,581
Location
Oregon
First Name
Eric
Truck Year
1980
Truck Model
K25
Engine Size
350-4bbl
Mine rides much better now than it did stock. It was originally a 1980 K25 8600GVW truck. I converted it to a single rear 31 Gallon tank and that gave me room to put in 63" GMT-400 3/4 ton rear leaf springs. You need to move the spring mount forward 4" to do that and the original 20 Gallon saddle tanks are in the way of that. I also put an ORD 2.5" shackle flip on at the same time. That combined for about 4" of lift in the rear while maintaining the carrying capacity, but it softened the ride considerably. I combined that with a Tuff Country EZ-Ride HD 4" spring in the front and an ORD sway bar disconnect. I only connect the sway bar when towing or with a heavy load in the bed, otherwise it is completely unnecessary and actually makes the ride much stiffer unloaded. It still rides like a 3/4 ton truck, but WAY better than stock.
 

midwest

Full Access Member
Joined
Dec 28, 2021
Posts
185
Reaction score
200
Location
Indiana
First Name
Scott
Truck Year
1986
Truck Model
K20
Engine Size
350
Thanks, sounds like you have helped yours. If I was driving mine all the time I might take those steps. At this point it spends 95 % of it's time in the garage and only sees a couple thousand miles a year. I was hoping I could just buy some new shocks and spend an hour making a difference. Sounds like that is not an option.
 

SirRobyn0

Full Access Member
Joined
Dec 6, 2019
Posts
6,755
Reaction score
11,402
Location
In the woods in Western Washington
First Name
Rob
Truck Year
1984
Truck Model
C20
Engine Size
305
Thanks, sounds like you have helped yours. If I was driving mine all the time I might take those steps. At this point it spends 95 % of it's time in the garage and only sees a couple thousand miles a year. I was hoping I could just buy some new shocks and spend an hour making a difference. Sounds like that is not an option.
I have 84' C20 and it has overloads, so it rides a little on the rougher side but like other folks I like it.

However I have a customer at the shop with a 77 C20 and when he is not hauling anything with it he runs 32psi in his front tires and 26psi in the back. I'm not sure I agree with 26 in the back, but if you are currently running 60, dropping to 32 or even 35 with cause the tires to flex a little more and make it ride a little smoother though there might be some handling trade off, you'd have to experiment.

Tires: if your currently running 6 plys or 8 plys, dropping down to LT tires would provide a bit better ride to, but you wouldn't be able to load up your truck heavy with lighter duty tires. Also if your tires are old the rubber hardens with age. So if these things are 15 or 20 year old they are going to have hardened quite a bit, and if they happen to be old enough to be bias tires, radials will definitely ride better.
 

Copymutt

Full Access Member
Joined
Jan 17, 2020
Posts
222
Reaction score
674
Location
Colorado
First Name
Jim
Truck Year
74
Truck Model
K20
Engine Size
350
Experienced the ride quality of various tires at a dealership.
Brand new F150’s, same trim level. First one rode like a barkalounger. Second one over same test drive would transmit every road imperfection to the steering wheel & to a lesser degree the seat.
First truck had Michelin P rated tires.
 

SirRobyn0

Full Access Member
Joined
Dec 6, 2019
Posts
6,755
Reaction score
11,402
Location
In the woods in Western Washington
First Name
Rob
Truck Year
1984
Truck Model
C20
Engine Size
305
Experienced the ride quality of various tires at a dealership.
Brand new F150’s, same trim level. First one rode like a barkalounger. Second one over same test drive would transmit every road imperfection to the steering wheel & to a lesser degree the seat.
First truck had Michelin P rated tires.
My point exactly. Most of the C20 series trucks should be getting D rated tires, I choose E rated tires, because I do load the truck up from time to time and wanted the extra compacity for piece of mind in that scenario, but all for the added stability when towing. I advised LT tires, but if the OP really doesn't haul loads then P rated would be the softest time. Makes a big difference, but there is a trade off for sure.
 

Grit dog

Full Access Member
Joined
May 18, 2020
Posts
6,981
Reaction score
12,246
Location
Auburn, Washington
First Name
Todd
Truck Year
1986, 1977
Truck Model
K20, C10
Engine Size
454, 350
My point exactly. Most of the C20 series trucks should be getting D rated tires, I choose E rated tires, because I do load the truck up from time to time and wanted the extra compacity for piece of mind in that scenario, but all for the added stability when towing. I advised LT tires, but if the OP really doesn't haul loads then P rated would be the softest time. Makes a big difference, but there is a trade off for sure.
Doesn’t really matter what load rating of tires are being used. Just adjust the pressure for the load or conditions or the ride quality.
Short of having med duty tires like 19.5s that have a rather high min pressure requirement, any LT tire (that designation is inclusive of all load ranges in the typical 16-20” rim sizes (and larger) can be aired down reasonably as seen fit for the load or ride.
Behind that, OP just needs new springs. The more expensive they are, the softer/better ride quality you can get.
And as mentioned above, the rear is upgradeable to newer longer OE springs which will help. And likely cheaper than high $ new aftermarket springs.
 

Snoots

Full Access Member
Joined
Jan 23, 2013
Posts
8,754
Reaction score
18,209
Location
Georgia
First Name
Roger
Truck Year
1973
Truck Model
Jimmy Sierra
Engine Size
350 w/203
I don't think Buick made a truck.
 

Forum statistics

Threads
44,193
Posts
951,219
Members
36,315
Latest member
aubiexx
Top