Rear leaf to Rear Coil conversion????? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72bigblock4wd · 05-24-2004, 10:04 PM

Rear leaf to Rear Coil conversion?????

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I have a '67 GMC c15 frame and am taking the body off for a 4wd truck that I'm building. I just found out that my wife's cousin has a '67 Chevy C10 that he's interested in selling, i.e., he'll make me a pretty good deal. The problem is that the frame on his truck is pretty rusty and has rear coils. The frame I have is really solid, but has rear leafs. I would like to swap the rear coil setup onto the rear leaf frame that I have (as well as doing a SWB conversion). Has anyone swapped from leafs to coils, and if so how difficult is the conversion? I want to swap it out so I can dump the '67 in the weeds with a 4.5"/4" drop.
Thanks

Longhorn Man · 05-24-2004, 10:54 PM

I am not sure on the leaf to coil deal, it has been said on here that it can be done, and it has been said that the frames are not the same.
However, if the frame is rusted, chances are the trailing arms are total junk too. Looking at your geographical location makes me think even more that the arms are rusted out.

At the minimum, it is something to look at on the 2 wheel drive truck.

Gotta71C20 · 05-25-2004, 11:47 AM

I'm in the process of restoring a C20 leaf spring truck and I have made the change to coils. It isn't too difficult but you will have a lot of rivets to grind off and drive out and a lot of holes to drill. I think I used about 120 3/8" bolts, nuts, washers to put the coil spring stuff on my frame. One rear crossmember changes out and be sure you have the coil frame around for measurements as you go. You will have to have the coil rear end also. Good luck. Larry

Yellow Cheyenne · 05-25-2004, 01:30 PM

I've done the conversion from coils to leafs (had bad trailing arms and a cheap donor frame with leafs). Not terribly difficult, but took some time, and as mentioned, used lots of bolts. Defenitely have a complete donor to pull all of the little items you will need such as frame braces, e-brake cables, brackets, etc. Just some info, all 4 X 4 pickups were leaf from the factory. The 4 X 4 leaf frames are different than the 2 WD leaf frames. The 2 WD frames are the same whether they use coils or leafs. All of this info is based on 2WD long bed 1/2 ton info-that's what I worked on. I can only guess that it would apply to the short bed and 3/4 ton pickups too.

68C15 · 05-25-2004, 02:10 PM

Gotta 71C20 is right. you will own stock in hdwr. store when done. it is not complicated, esp. with bed off both trucks. take whole assy from donor & set in place using trailing arms as locating points. leave bushing thru bolts loose. move back from there. if going this route I highly suggest air bags & engineer shock mounts differently so they are almost straight up & down. when these things are lowered the shocks become useless due to the low angle. put them behind axle mounting to U-bolt plate. makes for a much better ride.

Todd

72bigblock4wd · 05-26-2004, 07:20 PM

Thanks for the information everyone. Unfortunately I went to look at the other truck and the frame was pretty rusty so I won't be doing the conversion after all.

Hooter · 05-27-2004, 12:19 AM

well all you need is the coils and trailing arms, if the arms are fine, then torch them off the rusty frame and start putting them onto your leaf frame

05-24-2004, 10:04 PM	#1
72bigblock4wd Registered User Join Date: Feb 2004 Location: Grand Rapids, Michigan Posts: 194	Rear leaf to Rear Coil conversion????? Rear leaf to Rear Coil conversion????? -------------------------------------------------------------------------------- I have a '67 GMC c15 frame and am taking the body off for a 4wd truck that I'm building. I just found out that my wife's cousin has a '67 Chevy C10 that he's interested in selling, i.e., he'll make me a pretty good deal. The problem is that the frame on his truck is pretty rusty and has rear coils. The frame I have is really solid, but has rear leafs. I would like to swap the rear coil setup onto the rear leaf frame that I have (as well as doing a SWB conversion). Has anyone swapped from leafs to coils, and if so how difficult is the conversion? I want to swap it out so I can dump the '67 in the weeds with a 4.5"/4" drop. Thanks

05-25-2004, 11:47 AM	#3
Gotta71C20 Registered User Join Date: Dec 2000 Location: Belfair, Wa. USA Posts: 80	Leaf to coil I'm in the process of restoring a C20 leaf spring truck and I have made the change to coils. It isn't too difficult but you will have a lot of rivets to grind off and drive out and a lot of holes to drill. I think I used about 120 3/8" bolts, nuts, washers to put the coil spring stuff on my frame. One rear crossmember changes out and be sure you have the coil frame around for measurements as you go. You will have to have the coil rear end also. Good luck. Larry

05-25-2004, 01:30 PM	#4
Yellow Cheyenne Registered User Join Date: Jun 2001 Location: Eastern Kansas Posts: 488	I've done the conversion from coils to leafs (had bad trailing arms and a cheap donor frame with leafs). Not terribly difficult, but took some time, and as mentioned, used lots of bolts. Defenitely have a complete donor to pull all of the little items you will need such as frame braces, e-brake cables, brackets, etc. Just some info, all 4 X 4 pickups were leaf from the factory. The 4 X 4 leaf frames are different than the 2 WD leaf frames. The 2 WD frames are the same whether they use coils or leafs. All of this info is based on 2WD long bed 1/2 ton info-that's what I worked on. I can only guess that it would apply to the short bed and 3/4 ton pickups too. __________________ '72 Cheyenne. AC, PS, PB, Rear slider window, tilt. Light yellow (grapefruit yellow according to new sales literature from '72) '56 Chevy short step V-8 (My dad bought it new!!) '70 Olds 442 convertible '70 Olds Rallye 350

05-25-2004, 02:10 PM	#5
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	Gotta 71C20 is right. you will own stock in hdwr. store when done. it is not complicated, esp. with bed off both trucks. take whole assy from donor & set in place using trailing arms as locating points. leave bushing thru bolts loose. move back from there. if going this route I highly suggest air bags & engineer shock mounts differently so they are almost straight up & down. when these things are lowered the shocks become useless due to the low angle. put them behind axle mounting to U-bolt plate. makes for a much better ride. Todd __________________ Man rule #77...if you own a 67 stepside with a caddy 472 you will never be in danger of loosing you man card Last edited by 68C15; 05-25-2004 at 02:12 PM.

05-27-2004, 12:19 AM	#7
Hooter My other Love Join Date: Aug 2001 Location: Castlegar B.C. Canada Posts: 4,085	well all you need is the coils and trailing arms, if the arms are fine, then torch them off the rusty frame and start putting them onto your leaf frame __________________ Castlegar B.C.The great white North (Canada Eh!) Hooter_5@hotmail.com First generation Monte Carlo club pictures of my life

05-24-2004, 10:54 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	I am not sure on the leaf to coil deal, it has been said on here that it can be done, and it has been said that the frames are not the same. However, if the frame is rusted, chances are the trailing arms are total junk too. Looking at your geographical location makes me think even more that the arms are rusted out. At the minimum, it is something to look at on the 2 wheel drive truck.

05-26-2004, 07:20 PM	#6
72bigblock4wd Registered User Join Date: Feb 2004 Location: Grand Rapids, Michigan Posts: 194	Thanks for the information everyone. Unfortunately I went to look at the other truck and the frame was pretty rusty so I won't be doing the conversion after all.



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