The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 01-07-2009, 12:26 PM   #26
myoldchevytruck
Retired Air Force Veteran
 
myoldchevytruck's Avatar
 
Join Date: Aug 2007
Location: Pembroke Pines, Florida 33024
Posts: 1,808
Re: Rear suspension leaf to coil swap?

Quote:
Originally Posted by gringoloco View Post
I did my pickup. It was pretty easy. Plan on spending an entire weekend if you clean/paint while you're in there...




I also did the swap on my 69' Stepside. Bought the crossmember brackets and Track Bar Frame Mounts from a board member. I used Grade 8 hardware to reattach all of the mounts and brackets.

I installed 6 inch drop coils (No C-Notch) from GMC Pauls and a Super Track Bar from ECE.

As for the leaf spring axle brackets. I originally purchased Axle Saddle Brackets (For the train arms) from ECE for $29 plus shipping but ended up finding a Front/Rear 5 Lug Setup from a 72'. Now I also have front disk brakes.

Degree of difficulty? I'm just a DIY guy with average skills and with all of the parts ready to install, like Gringoloco said, It'll take the weekend to complete including cleaning and painting.
__________________
Harry
69' SWB Step Side 1/2 Ton w/68' Front Clip
Swap from Leafs to Trailing Arms (Complete)
Swap 6 Lug to 5 Lug (w/ Disk Brakes in Front)
3/6 Drop

Help Support The Board
Click Here For Information On How To Subscribe


Krue's FAQ Page

Vendors
myoldchevytruck is offline   Reply With Quote
Old 01-10-2009, 02:12 PM   #27
LUV2XCLR8
The LuvShack Garage
 
LUV2XCLR8's Avatar
 
Join Date: Jan 2004
Location: Maple Grove, TN (West Side)
Posts: 30,468
Re: Rear suspension leaf to coil swap?

Quote:
Originally Posted by myoldchevytruck View Post
I
I installed 6 inch drop coils (No C-Notch) from GMC Pauls and a Super Track Bar from ECE.
Sorry to hijack, but does it bottom out at all? What size rims? overall diameter? Thanks
__________________
Owner/Op: "TN Classic Transport Carriers"
The Toy: "Square Vette" 72 Hybrid Blazer
Toy Barn: "LuvShack" 40 x 60 x 20 Shop
Tow Piggy:"Maddy" 88 Silverado 3500
Hauler: "Feathers" 14 Aluma 8218T
LUV2XCLR8 is offline   Reply With Quote
Old 01-10-2009, 04:48 PM   #28
BradE
yard boy
 
BradE's Avatar
 
Join Date: Sep 2007
Location: Franklin, TN
Posts: 119
Re: Rear suspension leaf to coil swap?

Quote:
Sorry to hijack, but does it bottom out at all? What size rims? overall diameter? Thanks

x2!
__________________
1984 Chevy c20
BradE is offline   Reply With Quote
Old 01-10-2009, 04:57 PM   #29
oldspowered
resto body guy
 
Join Date: Mar 2008
Location: milford, Nebraska
Posts: 128
Re: Rear suspension leaf to coil swap?

i guess i don't under stand why switch to coil springs i would love to have leafs!!!
__________________
http://i3.photobucket.com/albums/y86...DSC_0004-2.jpg
trucks are ment to haul!
oldspowered is offline   Reply With Quote
Old 01-10-2009, 05:35 PM   #30
SCOTI
Registered User
 
SCOTI's Avatar
 
Join Date: Apr 2001
Location: DALLAS,TX
Posts: 22,080
Re: Rear suspension leaf to coil swap?

Quote:
Originally Posted by oldspowered View Post
i guess i don't under stand why switch to coil springs i would love to have leafs!!!
Why?
__________________
67SWB-B.B.RetroRod
64SWB-Recycle
89CCDually-Driver/Tow Truck
99CCSWB Driver
All Fleetsides
@rattlecankustoms in IG

Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive.
It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar.....

Cubic inches is like Indiana Jones with a cheap pistol.
SCOTI is offline   Reply With Quote
Old 01-11-2009, 05:27 AM   #31
oldspowered
resto body guy
 
Join Date: Mar 2008
Location: milford, Nebraska
Posts: 128
Re: Rear suspension leaf to coil swap?

leafs you can hold more weight!
__________________
http://i3.photobucket.com/albums/y86...DSC_0004-2.jpg
trucks are ment to haul!
oldspowered is offline   Reply With Quote
Old 01-11-2009, 09:07 AM   #32
myoldchevytruck
Retired Air Force Veteran
 
myoldchevytruck's Avatar
 
Join Date: Aug 2007
Location: Pembroke Pines, Florida 33024
Posts: 1,808
Re: Rear suspension leaf to coil swap?

Quote:
Originally Posted by LUV2XCLR8 View Post
Sorry to hijack, but does it bottom out at all? What size rims? overall diameter? Thanks
Quote:
Originally Posted by BradE View Post
x2!
Sorry for the late response guys. No, it does not bottom out. As for wheel size, there just 15x7 inch steel wheels. Installing some new shocks within the next week, I'll post some pics.
__________________
Harry
69' SWB Step Side 1/2 Ton w/68' Front Clip
Swap from Leafs to Trailing Arms (Complete)
Swap 6 Lug to 5 Lug (w/ Disk Brakes in Front)
3/6 Drop

Help Support The Board
Click Here For Information On How To Subscribe


Krue's FAQ Page

Vendors
myoldchevytruck is offline   Reply With Quote
Old 01-11-2009, 02:09 PM   #33
SCOTI
Registered User
 
SCOTI's Avatar
 
Join Date: Apr 2001
Location: DALLAS,TX
Posts: 22,080
Re: Rear suspension leaf to coil swap?

Quote:
Originally Posted by oldspowered View Post
leafs you can hold more weight!
You mean you can overload leafs more than you can coils. Both are rated to safely carry the same weight capacity.
__________________
67SWB-B.B.RetroRod
64SWB-Recycle
89CCDually-Driver/Tow Truck
99CCSWB Driver
All Fleetsides
@rattlecankustoms in IG

Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive.
It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar.....

Cubic inches is like Indiana Jones with a cheap pistol.
SCOTI is offline   Reply With Quote
Old 01-11-2009, 03:34 PM   #34
mr48chev
Registered User
 
mr48chev's Avatar
 
Join Date: Jul 2007
Location: Toppenish, WA
Posts: 15,730
Re: Rear suspension leaf to coil swap?

Quote:
Originally Posted by oldspowered View Post
leafs you can hold more weight!
Horrors You don't really think any of the guys swapping to dropped coils intend to carry anything heavier than a duffel bag and cooler in those trucks.

I have to agree that for serious towing or hauling I would rather have the leaf springs as I feel they are more stable.
mr48chev is offline   Reply With Quote
Old 01-11-2009, 05:37 PM   #35
SCOTI
Registered User
 
SCOTI's Avatar
 
Join Date: Apr 2001
Location: DALLAS,TX
Posts: 22,080
Re: Rear suspension leaf to coil swap?

Quote:
Originally Posted by mr48chev View Post
Horrors You don't really think any of the guys swapping to dropped coils intend to carry anything heavier than a duffel bag and cooler in those trucks.

I have to agree that for serious towing or hauling I would rather have the leaf springs as I feel they are more stable.
Drop coils can compromise your ability to carry the full load these 1/2 ton truck are rated for. That's why airbags allow the best of both worlds & w/a coil suspension, it's as easy as swapping the springs out.

I have (had) 2 swb trucks that were both dropped w/their specific suspensions. I could not tell a difference between the 2 as they both handled towing my 18ft car trailer w/o a problem. The 68 still gets the nod for better ride....... no competition.
__________________
67SWB-B.B.RetroRod
64SWB-Recycle
89CCDually-Driver/Tow Truck
99CCSWB Driver
All Fleetsides
@rattlecankustoms in IG

Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive.
It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar.....

Cubic inches is like Indiana Jones with a cheap pistol.
SCOTI is offline   Reply With Quote
Old 01-11-2009, 10:15 PM   #36
boilrman
70 Chevy 3/4t
 
Join Date: Sep 2000
Location: Kokomo,IN USA
Posts: 1,230
Re: Rear suspension leaf to coil swap?

my question is almost the same. I have a C20 with coils. I would like to change out the eaton rear and drop in a dana rear. The dana is a leaf sprung rear. After I cut off the mounts, how do I know what angle to set it at so I dont bind the driveshaft?
__________________
Find a job you love and you'll never have to work a day in your life.
1998 Yamaha V-Star 650
1970 Chevy 3/4t, I6 (rebuilt), 4 speed
Kokomo,IN
boilrman is offline   Reply With Quote
Old 01-11-2009, 10:21 PM   #37
SCOTI
Registered User
 
SCOTI's Avatar
 
Join Date: Apr 2001
Location: DALLAS,TX
Posts: 22,080
Re: Rear suspension leaf to coil swap?

Quote:
Originally Posted by boilrman View Post
my question is almost the same. I have a C20 with coils. I would like to change out the eaton rear and drop in a dana rear. The dana is a leaf sprung rear. After I cut off the mounts, how do I know what angle to set it at so I dont bind the driveshaft?
Measure the pinion angle of the current set-up @ the pinion yoke before swapping the 'new' housing into place. Set-up the new housing @ the same angle.
__________________
67SWB-B.B.RetroRod
64SWB-Recycle
89CCDually-Driver/Tow Truck
99CCSWB Driver
All Fleetsides
@rattlecankustoms in IG

Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive.
It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar.....

Cubic inches is like Indiana Jones with a cheap pistol.

Last edited by SCOTI; 01-11-2009 at 10:22 PM.
SCOTI is offline   Reply With Quote
Old 01-12-2009, 03:01 PM   #38
kcjones
I wish I was a cowboy
 
kcjones's Avatar
 
Join Date: Apr 2008
Location: Rohnert Park, CA
Posts: 409
Re: Rear suspension leaf to coil swap?

Quote:
Originally Posted by boilrman View Post
my question is almost the same. I have a C20 with coils. I would like to change out the eaton rear and drop in a dana rear. The dana is a leaf sprung rear. After I cut off the mounts, how do I know what angle to set it at so I dont bind the driveshaft?
I just completed a very similar swap (Eaton HO52 to '74 12bolt [leafs]), and did as much research ahead of time as I could. Here's a few things I learned:

1) Get it absolutely right. If you're off by more than 3 degrees or so, you'll have an AWFUL howling vibration that will make the truck impossible to drive and will trash your ujoints/driveshaft/center bearing in no time, and possibly screw up your pinion bearing.
2) The absolutely correct way to get the right pinion angle is to make sure the yoke to driveshaft angle is an exact mirror of the trans yoke to driveshaft angle. If you have a 2 piece, like you likely do in your C20, then make the rear end yoke to driveshaft angle exactly mirror the front driveshaft to rear driveshaft angle. So, for example, if the angle between the front and rear shafts of a 2 piece is negative (angles down) 7 degrees, make the rear shaft to pinion yoke angle positive 7 degrees.
3) If at all possible, tack weld in the new coil spring pads onto the rear end housing while you've got it all bolted up at ride height. Make sure everything is exactly as it'll be when you drive it, or as close as you can. Box is on, springs, shocks, panhard are all bolted up. I tried to bolt it all up, mark the correct location for the pads on the rear end housing, and then remove it to weld...after the weld, I was off a degree or 2. I shimmed to correct.
4) Measure again after the pads are welded and the whole thing is bolted back together. If there is any discrepancy, correct it using pinion angle shims (available via CPP). If you're off by more than 6 degrees, shims may not be a good idea because it'll bind the ubolts and put side to side pressure on them, instead of all up and down pressure, which they're designed/sized to handle.

Here's a picture of where to measure pinion angle for a 2 piece driveshaft:

Name:  PinionAngle.jpg
Views: 640
Size:  14.8 KB
__________________
-Kris

Met list: Cyclone,Wilson,TranzAm,extd56,hotrodhomi,mnky30,Rokcrln,Brad,JerryJones(well, his truck anyway).
kcjones is offline   Reply With Quote
Old 01-12-2009, 03:08 PM   #39
windmill
Registered User
 
windmill's Avatar
 
Join Date: Jan 2007
Location: Sylvania, Alabama
Posts: 288
Re: Rear suspension leaf to coil swap?

Got a question guys. Will a frame that has coils from factory have the holes for the leaf spring brackets?
__________________
72 swb pickup
http://i124.photobucket.com/albums/p...k/100_0958.jpg
1967 chevelle ss
1966 mustang getting a l33 ls motor
1969 chevy dump truck
1989 mustang 6.0 ls best time of 1.29 at 5.91
https://www.youtube.com/watch?v=JtbooZoGZmQ
windmill is offline   Reply With Quote
Old 01-13-2009, 05:54 PM   #40
truckintexas
Registered User
 
Join Date: Jul 2004
Location: Weatherford, TX
Posts: 225
Re: Rear suspension leaf to coil swap?

No. My '67 Frame did not have the holes I had to drill them. I used several reference points along the frame (such as the trans crossmember rivets) to measure where the center point of the rear differential should be. I also measured two other leaf spring trucks from the end of the frame to the nearest mounting hole on the rear bracket. In addition, I made sure the rubber bumper stops hit dead center on top of the axle. Mine is not on the road yet, so I can't give you the final verdict, but I think I got it right.

Last edited by truckintexas; 01-13-2009 at 05:55 PM.
truckintexas is offline   Reply With Quote
Old 01-17-2009, 08:06 AM   #41
boilrman
70 Chevy 3/4t
 
Join Date: Sep 2000
Location: Kokomo,IN USA
Posts: 1,230
Re: Rear suspension leaf to coil swap?

Quote:
Originally Posted by kcjones View Post
I just completed a very similar swap (Eaton HO52 to '74 12bolt [leafs]), and did as much research ahead of time as I could. Here's a few things I learned:

1) Get it absolutely right. If you're off by more than 3 degrees or so, you'll have an AWFUL howling vibration that will make the truck impossible to drive and will trash your ujoints/driveshaft/center bearing in no time, and possibly screw up your pinion bearing.
2) The absolutely correct way to get the right pinion angle is to make sure the yoke to driveshaft angle is an exact mirror of the trans yoke to driveshaft angle. If you have a 2 piece, like you likely do in your C20, then make the rear end yoke to driveshaft angle exactly mirror the front driveshaft to rear driveshaft angle. So, for example, if the angle between the front and rear shafts of a 2 piece is negative (angles down) 7 degrees, make the rear shaft to pinion yoke angle positive 7 degrees.
3) If at all possible, tack weld in the new coil spring pads onto the rear end housing while you've got it all bolted up at ride height. Make sure everything is exactly as it'll be when you drive it, or as close as you can. Box is on, springs, shocks, panhard are all bolted up. I tried to bolt it all up, mark the correct location for the pads on the rear end housing, and then remove it to weld...after the weld, I was off a degree or 2. I shimmed to correct.
4) Measure again after the pads are welded and the whole thing is bolted back together. If there is any discrepancy, correct it using pinion angle shims (available via CPP). If you're off by more than 6 degrees, shims may not be a good idea because it'll bind the ubolts and put side to side pressure on them, instead of all up and down pressure, which they're designed/sized to handle.

Here's a picture of where to measure pinion angle for a 2 piece driveshaft:

Attachment 420367
Excellent info. Much appreciated. Thanks
__________________
Find a job you love and you'll never have to work a day in your life.
1998 Yamaha V-Star 650
1970 Chevy 3/4t, I6 (rebuilt), 4 speed
Kokomo,IN
boilrman is offline   Reply With Quote
Old 01-17-2009, 08:35 AM   #42
LUV2XCLR8
The LuvShack Garage
 
LUV2XCLR8's Avatar
 
Join Date: Jan 2004
Location: Maple Grove, TN (West Side)
Posts: 30,468
Re: Rear suspension leaf to coil swap?

__________________
Owner/Op: "TN Classic Transport Carriers"
The Toy: "Square Vette" 72 Hybrid Blazer
Toy Barn: "LuvShack" 40 x 60 x 20 Shop
Tow Piggy:"Maddy" 88 Silverado 3500
Hauler: "Feathers" 14 Aluma 8218T
LUV2XCLR8 is offline   Reply With Quote
Old 01-17-2009, 04:53 PM   #43
windmill
Registered User
 
windmill's Avatar
 
Join Date: Jan 2007
Location: Sylvania, Alabama
Posts: 288
Re: Rear suspension leaf to coil swap?

Got a question guys......will the leaf springs out from under a 73 up truck the same as a 72 leaf spring setup.
__________________
72 swb pickup
http://i124.photobucket.com/albums/p...k/100_0958.jpg
1967 chevelle ss
1966 mustang getting a l33 ls motor
1969 chevy dump truck
1989 mustang 6.0 ls best time of 1.29 at 5.91
https://www.youtube.com/watch?v=JtbooZoGZmQ
windmill is offline   Reply With Quote
Old 01-17-2009, 05:39 PM   #44
SCOTI
Registered User
 
SCOTI's Avatar
 
Join Date: Apr 2001
Location: DALLAS,TX
Posts: 22,080
Re: Rear suspension leaf to coil swap?

Quote:
Originally Posted by windmill View Post
Got a question guys......will the leaf springs out from under a 73 up truck the same as a 72 leaf spring setup.
I believe the 73 up have wider leafs (2.5" vs. 2.25").
__________________
67SWB-B.B.RetroRod
64SWB-Recycle
89CCDually-Driver/Tow Truck
99CCSWB Driver
All Fleetsides
@rattlecankustoms in IG

Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive.
It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar.....

Cubic inches is like Indiana Jones with a cheap pistol.
SCOTI is offline   Reply With Quote
Old 01-17-2009, 05:57 PM   #45
windmill
Registered User
 
windmill's Avatar
 
Join Date: Jan 2007
Location: Sylvania, Alabama
Posts: 288
Re: Rear suspension leaf to coil swap?

not worried about the width, more of the length of the spring itself
__________________
72 swb pickup
http://i124.photobucket.com/albums/p...k/100_0958.jpg
1967 chevelle ss
1966 mustang getting a l33 ls motor
1969 chevy dump truck
1989 mustang 6.0 ls best time of 1.29 at 5.91
https://www.youtube.com/watch?v=JtbooZoGZmQ
windmill is offline   Reply With Quote
Old 01-18-2009, 12:21 PM   #46
gringoloco
A guy with a truck
 
gringoloco's Avatar
 
Join Date: Sep 2005
Location: Germany, for now
Posts: 5,921
Re: Rear suspension leaf to coil swap?

They will work. My truck was 73-87 stuff before I swapped back to coils...
__________________
-Chris

Instagram _elgringoloco_

'70 Short-Wide How to: Ruin a perfectly good C10
‘70 Blazer ConversionHow To: Ruin a Perfectly Good 4wd
'72 Highlander How To: Ruin a Perfectly Good K/5 (SOLD)
'72 Blazer 2WD How to: Ruin a perfectly good Blazer (SOLD)
'05 Yukon Daily Driven (not so stock) Yukon (SOLD)
‘07 Yukon Denali (daily)

Members met list: SCOTI, darkhorse970, 67cheby, 67cheby'sGirl, klmore, porterbuilt, n2billet, Fastrucken, classicchev, Col Clank, GSFMECH, HuggerCST, Spray-Bomb, BACKYARD88, 5150, fine69, fatbass, smbrouss70, 65StreetCruiser, GAc10boy
gringoloco is offline   Reply With Quote
Old 02-19-2009, 07:27 PM   #47
xjmtdew
Registered User
 
Join Date: Oct 2008
Location: co
Posts: 19
Re: Rear suspension leaf to coil swap?

Hey Guys I know this thread is a little old at this point but I just came across it as I am planning on swapping my C-20 with the trailing arms from a C-10 and running air bags in the back. My question is are the frames from a C-10 and C-20 similar enough in the area where the coil springs would mount to the frame match where the trailing arms cross the frame? If that makes sense ? Also when I mount the bags do I need any type of adapters? The bags I have are similar to the Firestone 2600's?

BTW this thread has answered alot of my questions so far. Great info here!!
xjmtdew is offline   Reply With Quote
Old 02-19-2009, 10:03 PM   #48
SCOTI
Registered User
 
SCOTI's Avatar
 
Join Date: Apr 2001
Location: DALLAS,TX
Posts: 22,080
Re: Rear suspension leaf to coil swap?

Quote:
Originally Posted by xjmtdew View Post
Hey Guys I know this thread is a little old at this point but I just came across it as I am planning on swapping my C-20 with the trailing arms from a C-10 and running air bags in the back. My question is are the frames from a C-10 and C-20 similar enough in the area where the coil springs would mount to the frame match where the trailing arms cross the frame? If that makes sense ? Also when I mount the bags do I need any type of adapters? The bags I have are similar to the Firestone 2600's?

BTW this thread has answered alot of my questions so far. Great info here!!
They made trailing arm suspension 3/4 tons (C20's) so yes the frames are similar.
__________________
67SWB-B.B.RetroRod
64SWB-Recycle
89CCDually-Driver/Tow Truck
99CCSWB Driver
All Fleetsides
@rattlecankustoms in IG

Building a small, high rpm engine with the perfect bore, stroke and rod ratio is very impressive.
It's like a highly skilled Morrocan sword fighter with a Damascus Steel Scimitar.....

Cubic inches is like Indiana Jones with a cheap pistol.

Last edited by SCOTI; 02-19-2009 at 10:04 PM.
SCOTI is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 09:56 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com